Does John have or has?

Excuse me, I'm a bit confused about the grammar in this sentence: "Does John have or has?" Could you clarify which verb form is more appropriate to use in this context? I understand that "does" is used with the base form of the verb when forming a question in present simple tense, but I'm not sure if "has" is correct as well or if it's a mistake. Could you please explain the correct way to phrase this question, and why it's important to use the right verb form? Thank you in advance for your help.