Firstly, they must accept the quote online. Once this is done, they are given the option to make the payment amount you have requested:

In the quote settings page, you can set the word(s) in the red area below to whatever you want (see the later section on this).

The client will then see two screens generated by Stripe, the first one for address details:

And the second for the card details:

This is on the online link that you will send the client. They can see the invoice and also a button to pay with a card:

You can set the word(s) in the square bracket on the invoice.

The stripe payment screens the client will see after this are the same as the quotes, where they will enter their address and card details.