Apple mail does not connect to Gmail account.

Ok, we understand that you typically use Apple Mail to access your Gmail account.

Let's see what is going on that is preventing it from accessing Gmail.

Have you tried using the Connection Doctor? Ref: Use Connection Doctor in Mail on Mac - Apple Support

Regardless, what was the result doing so?

Did you verify that you can access your Gmail account, via a web browser, as BobTheFisherman has asked?

If it can, then we verified that your Gmail account's user credentials are working properly. If not, then that needs to be resolved first.

Can you connect to your gmail account using the browser?

What have you tried for yourself? How did you set up the mail? Just via the easy route ( click google, and then email and password)

are you sure your password is correct? I have no problems with gmail and apple mail in particular.

To save some time, what steps have you tried, so far yourself, to resolve this issue so that we don't try offering potential solutions that may not have already worked for you? Do you see any error messages? Was this always an issue or just started to happen recently?