I need to copy the last 7 characters of the RITM number into a new field I created on sc_req_item

[Suzanne Coffman]

Based on this post Solved: Flow Designer - adding "substring to remove last c... - ServiceNow Community

and others I have tried a number of approaches to a script in the Update Requested Item Record action of a fb flow to copy the last 7 characters (the numeric part) of the RITM number into a new field I created on the sc_req_item table called u_contractor_id.

I am new to scripting

I have tried multiple variations of the following:

return substring(fd_data.trigger.request_item.number,4,7)

and

var a = fd_data.trigger.request_item.number;

//var st = a.toString(); it should already be a string?

var cid = a.substring(4,7)

//gs.print(cid);

Suggestions?  

[Suzanne Coffman]

The transform approach worked.  Neither script worked.

But that's fine, I'd rather avoid using scripts anyway.

It turns out the "not a valid record" error I kept getting was do to a bad catalog variable.