Exchange SMTP modern authentication OAuth

I have a web app which sends emails, using SMTP to an exchange account I have with one of my clients. They recently moved to requiring two factor authentication (2FA) and this is now broken.

One solution is using App Passwords but I don’t think my client has this set up.

Is there a way of doing this using OAuth instead?

Both the Chilkat plugin and CURL with the MBS plugin support OAuth. But I’m not sure if they work with a web app.

I think we have oAuth examples.
And for SMTP; you may do the oAuth and then get the token to pass to our CURL class.

Thanks for the info.
By the way, @Christian_Schmitz it looks as if you asked this very same question back in 2017: Did you ever get a reply?

Sorry, no.

And I haven’t had myself a mail account with oAuth to try it.