How to set up one page checkout in VirtueMart?

Question

CMS

The store is being migrated from Joomla 2 to Joomla 3. We need to make the checkout the same as it was in J2, but the plugin and customization that was used under J2 does not fit under J3.

Under J2, it looks like this:
1) the buyer enters his full name, email, phone number and delivery address in the cart.

2) After placing an order, a user is created in Joomla, whose username is email, name is full name, a password is generated automatically, an email is sent with registration data in the store. A separate letter with order data is also sent.

I tried to repeat this algorithm in j3.
The "guest" checkout mode is not suitable, since it does not create a Joomla user, so I turned off the guest checkout mode.
To implement a one-page order, I installed the VP One Page Checkout 6.5.1 plugin.
One of his templates allows you to make such a trick:

But this way you get a lot of fields to fill out, and some data must be entered several times, and the button must be pressed twice.
I wanted to hide the first block and made a jQuery script so that when filling out the second block (full name, email and phone number), the data is copied to the registration form and the registration button is pressed automatically.
But after pressing the button, automatic authorization occurs and the filled fields again become empty.
I've run out of ideas.

Joomla ‎3.9.16
VirtueMart 3.6.10 10211

Answer 1

Here is a good solution for one page shopping cart - One Page Checkout for VirtueMart . A lot of useful settings and features. Supports Russian.