Delay session form send data until payment is processed

Hello

I’m trying to construct a WordPress based website which will allow session based form entries. The data from the forms, however, should not actually be sent until the user has progressed onwards through the session to the point at which a payment is processed.

So somehow the form needs to temporarily store the data – either client or server side, until there is confirmation of that payment received. (And in the event that the user does not take the session through to payment – that stored data needs to be destroyed).

I’m fairly new to WordPress – having only developed some fairly basic websites. Have not attempted anything as ‘dynamic’ as this…

Could anyone knowledgable advise on general architecture, and appropriate plugins that might help achieve this, please?

Thank-you!