Previous and next forms inside tabs, then pay

Hello community!

On a particular CMS template page, I have 3 tabs with forms, the 1st one for infos, the 2nd for billing, and the 3rd one: not a form but a summary of the two previous entries.
Here’s the thing : I have created buttons, like a “next” on the 1st tab, which I’d like to direct towards tab2, “previous” and “next” on tab2, etc…
I found this topic but I cant fully comprehend the method behind: Button inside a tab Link to the next tab - #6 by NAA

For now, I have id’ed my tabs and set up a in-page linking to the next or previous tab, but it actually scroll up at the tab level, not go onto the next.

I also wonder how to proceed to make the 3rd tab recap all the infos that were entered in tabs 1&2, as a summary.

Lastly I tried to set up a payment button as I want the last submit to direct to a payment page, but it says it can only be done on a product page. The idea is you browse through courses we offer, select one, get to the register template page, go through the forms, and pay.

Did I do the CMS register template for nothing while I should have created the courses on Product pages to be linked to? I feel like I am understanding something but I’d like confirmation.

I am no stranger to a little bit of custom code whenever needed but I’d need to grasp the mechanics behind it.
Any help would be greatly appreciated
Thanks guys!

Here is my public share link: Webflow - European Institute of Digital Law