Session restart after non-csrf iframe form

Hey!

I'm trying to add a payement solution, but the system is an API. I call this API in my blade file (in script), then the script call an iframe to render the payement system.

The problem:

When the user ends the transaction, the API redirects the user to a specific route to process the User Account. But surprise, there is no more User :)

I've tried to put csrf in meta. I've tried too to put the id of user in the $_POST['custom'], the only variable that the API give us then I wanted to restore the session but nothing.

I dont have more ideas, so if you have one <3

Thanks u so much.