Here are the different translations and at the bottom I will post the root word and other verses that show why I believe it is about obedience.
John 3:36
19 translations render it is “disobedience” - 6 translations render it as “unbelief”
New International Version
Whoever believes in the Son has eternal life, but whoever rejects the Son will not see life, for God's wrath remains on them.
New Living Translation
And anyone who believes in God's Son has eternal life. Anyone who doesn't obey the Son will never experience eternal life but remains under God's angry judgment."
English Standard Version
Whoever believes in the Son has eternal life; whoever does not obey the Son shall not see life, but the wrath of God remains on him.
Berean Study Bible
Whoever believes in the Son has eternal life. Whoever rejects the Son will not see life. Instead, the wrath of God remains on him."
Berean Literal Bible
The one believing in the Son has eternal life, but the one not obeying the Son will not see life, but the wrath of God abides on him."
New American Standard Bible
"He who believes in the Son has eternal life; but he who does not obey the Son will not see life, but the wrath of God abides on him."
King James Bible
He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him.
Holman Christian Standard Bible
The one who believes in the Son has eternal life, but the one who refuses to believe in the Son will not see life; instead, the wrath of God remains on him.
International Standard Version
The one who believes in the Son has eternal life, but the one who disobeys the Son will not see life. Instead, the wrath of God remains on him.
NET Bible
The one who believes in the Son has eternal life. The one who rejects the Son will not see life, but God's wrath remains on him.
New Heart English Bible
Whoever believes in the Son has eternal life, but whoever refuses to believe in the Son won't see life, but the wrath of God remains on him."
Aramaic Bible in Plain English
Whoever is trusting in The Son, has The Eternal Life, and whoever disobeys The Son shall not see The Life, but the anger of God shall abide upon him.”
GOD'S WORD® Translation
Whoever believes in the Son has eternal life, but whoever rejects the Son will not see life. Instead, he will see God's constant anger."
New American Standard 1977
“He who believes in the Son has eternal life; but he who does not obey the Son shall not see life, but the wrath of God abides on him.”
Jubilee Bible 2000
He that believes in the Son has eternal life, and he that does not obey the Son shall not see life, but the wrath of God abides on him.
King James 2000 Bible
He that believes on the Son has everlasting life: and he that believes not the Son shall not see life; but the wrath of God abides on him.
American King James Version
He that believes on the Son has everlasting life: and he that believes not the Son shall not see life; but the wrath of God stays on him.
American Standard Version
He that believeth on the Son hath eternal life; but he that obeyeth not the Son shall not see life, but the wrath of God abideth on him.
Douay-Rheims Bible
He that believeth in the Son, hath life everlasting; but he that believeth not the Son, shall not see life; but the wrath of God abideth on him.
Darby Bible Translation
He that believes on the Son has life eternal, and he that is not subject to the Son shall not see life, but the wrath of God abides upon him.
English Revised Version
He that believeth on the Son hath eternal life; but he that obeyeth not the Son shall not see life, but the wrath of God abideth on him.
Webster's Bible Translation
He that believeth on the Son, hath everlasting life: and he that believeth not the Son, shall not see life; but the wrath of God abideth on him.
Weymouth New Testament
He who believes in the Son has the Life of the Ages; he who disobeys the Son will not enter into Life, but God's anger remains upon him.
World English Bible
One who believes in the Son has eternal life, but one who disobeys the Son won't see life, but the wrath of God remains on him."
Young's Literal Translation
he who is believing in the Son, hath life age-during; and he who is not believing the Son, shall not see life, but the wrath of God doth remain upon him.'
John 3:36, “He who believes in the Son possesses everlasting life, but he who does not obey the Son shall not see life, but the wrath of Yah remains on him.”
“does not obey” is word #544 - apeitheó: to disobey, Original Word: ἀπειθέω, Part of Speech: Verb, Transliteration: apeitheó, Phonetic Spelling: (ap-i-theh'-o), Short Definition: I disobey, rebel, am disloyal, Definition: I disobey, rebel, am disloyal, refuse conformity.
“does not obey” is word G544 ἀπειθέω apeitheo (a-pei-the'-ō) v., 1. to disbelieve (willfully and perversely)., 2. (by direct extension) to be willfully disobedient., [from G545], KJV: not believe, disobedient, obey not, unbelieving , Root(s): G545
John/Yahanan 5:46-47, "For had you believed Mosheh, you would have believed Me, for he wrote about Me*. But if you do not believe his writings, how will you believe My words?"
*Mosheh wrote:
Deuteronomy 18:18-19, "I (YHWH) will raise up for them a Prophet (Yahshua/Jesus) like you from among their brothers, and I will put My words in His mouth, and He will tell them everything I command Him. Whoever will not listen to My words, which He speaks in My Name, I will judge him for it"
"listen" is word #8085 - שָׁמַעshama` {shaw-mah'}
Brown-Driver-Briggs (Old Testament Hebrew-English Lexicon)
A primitive root; to hear intelligently (often with implication of attention, obedience, etc.; causatively to tell, etc.)
Hebrew Word Study (Transliteration-Pronunciation Etymology & Grammar) - 1) to hear, listen to, obey
John/Yahanan 12:48, "He who rejects Me, and does not follow My words has One Who judges him. The word that I have spoken, the same will be used to judge him in the last day."