I have really tired looking for the information i need and hope for your help.
Also, i have written to Stripe support, but for now the communication with them is very difficult.

Let's start at the very beginning.

I use Stripe subscriptions with Laravel Cashier.

I have already finished the payment with credit/debit cards. It has such a workflow:
- user fills the form;
- Stripe.js sends the filled data to Stripe server and returns the paymentMethod;
- then i send the paymentMethod to my server and make the subscription for user with/without trial days.

I need to add Google pay and Apple pay buttons.
According to the Stripe docs about [Google pay](https://stripe.com/docs/google-pay#web) and [Apple pay](https://stripe.com/docs/apple-pay#web), i have to create the [Payment Request Button](https://stripe.com/docs/stripe-js/elements/payment-request-button).
As i understand the docs about Payment Request Button it works by this way:
- server-side creates paymentIntent and sends it to the client-side;
- the user pushes the Payment Request button;
- the browser opens a popup with saved user's cards;
- the user chooses a card and stripe.js charges user instantly.

I can't understand on what step stripe knows the plan id for making a subscription for the user.

I don't need to charge user instantly, i need just get the paymentMethod to send it to the server-side.
Does anyone have experience with making Stripe subscriptions with Payment Request button?

I would be very appreciated for the help.