Handling Submission in Auth0 Forms with Custom HTML Block + Accessing context, fields, etc. in Script

I’m using Auth0 Forms triggered via a Post-Login Action, and I’ve built the form entirely using a custom HTML block (not field blocks). I’ve added standard HTML inputs, but I’m unsure how to handle the form submission so it continues with the next flow properly.

Also, how can I access Auth0 variables like:
{{context.*}}, {{fields.*}}, {{vars.*}}, {{actions.*}}, and {{functions.*}}
inside a custom <script> block when using an HTML block?

Has anyone found a workaround or best practice for this setup