User Session variables to recall after form submit & redirect to menu

User Session variables to recall after form submit & redirect to menu

Hey,
Forgive me if this is a simple answer I have overlooked.

I have built a big onboarding process for my SAAS platform which is built and managed by an external Dev team.

I am hoping to embed my new creator app on the SAAS platform.

I have a menu page with multiple forms linked to panels on the menu

I believe my forms are stateless (no records kept) on form load I GET SassSettings and on submit i POST/PUT updates settings then on submit redirect back to Menu.

the orignal menu page script gets the customerId and actionKey from the parent page

<p><iframe frameborder="0" height="1500" id="XXXXX" scrolling="no" src="https://creatorapp.zohopublic.com.au/XXXXXXXX?customerId=##contactId##&amp;actionKey=##actionKey##" style="border: 0; display: block;" width="100%"></iframe></p>

THE ISSUE:
i cant redirect on submit with the customerId and actionKey vals so when the user returns to the menu the app doesnt know who they are.