I would like to create a script that will create a new record in Database_A and then set Field_X in Database_B = to the primary key in Database_A. After Field _X in Database_B is set it will link the two databases.

It has been recommended that we should not use the copy and paste script steps, but I am having difficulty getting the script to work without these steps.

Is there a better way to script this link without the use of copy/paste?

Any

You are going aout it the wrong way, and making it seem more complicated that it needs to be.

In the relationship between Database A and B, check the option to allow related records to be created in Database B.

Now the portal will have a blank row at the bottom. This allow you to create related records, and FMP automatically manages the entering of the primary keys for you.