Access session storage manager from API action file

Apologies to all if this is really dumb.

I have a series of API calls I have to make on a reciept page from an external payment processor.

The way the system I’m pushing data to is that I have a series of multiple API’s I have to send data to in order (create contract --> Get Contract ID returned --> Pass ContractID in new API call to set the dollar value from the purchase, and so on)

I have all the variables saved as Session Storage (since this helps me keep everything consistent across the multiple page hops I hvae to take out of my system to the CC processor and back again).

My question is have an api action set up that I’ll run through these multiple API’s. . but from there I can’t access the Session Storage variables. I

I tried running it as an app flow in the page but I couldn’t grab any of the output from the previous API to pass to the next one.

Is there anything I’m obviously missing? Or is there any way I can accomplish this. The only think I can think of is to use hidden form fields to grab the Session Variables on page load and then I can access them via linked form in the API but that seems. . .convoluted.

Any thoughts? And again, apologies if I’m being obtuse but I’ve been slamming at this for hours and my brain has gone soft.

Thanks