How to implement multi-steps form with Advanced Custom Fields (only code) for custom theme

Question

How can I create a pagebreak or multi-step form with ACF?

I'have created a long form with ACF code in the template files, so i'm not using groups from ACF plugin.

Now I want to create multi-steps for the user to fill out the form in multi steps and that the form would save each time a section is done.

Thanks in advance!