@StephChen - from a user here
welcome to the Community!
yes you are correct, you can only have one Stripe payment question in typeform.
The way to get around this is to ask the questions of how many people are going to attend, determine the price you will charge by using logic and calculations and then pass the total value to the @price variable, which is then picked up on the payment question by Stripe.
When I was trying to figure out how to set up a small t-shirt ordering capability, I had to do all my mock-ups with Statement questions ‘replacing' the Payment questions until i worked out all my logic. Once i had my logic worked out, i then made a copy of my form, replaced the statement page with the payment question (after setting up my stripe account) and then i was live.
if you want to see how i did this, as an example, the test form is at this link - because i wanted to allow the user to select up to three different tshirts, it has some additional features in it that assemble the final payment amount.
i hope this helps somewhat
cheers
des