From Hubspot to Mailpoet

I have a custom newsletter sign-up form with a custom JS + CSS based UX (e.g. Step 1 = enter email, and Step 2 = check off GDPR consent “stuff”. But step 2 won’t be exposed until a valid email is entered.)

In any case, this form was originally setup to work with Hubspot (via an AJAX based submit). Would it be possible to switch to MailPoet? Does MP support custom forms?

I understand there’s likely some custom dev necessary, which is obviously understandable ?? But maybe this isn’t something MP supports? Best case, the MP WP plugin has hooks that can be utilized? If so, links to the appropriate page(s) in the MP docs would be greatly appreciated.