Loading Lookup Data into Model Driven PowerApps Custom Entities

Question

I am trying to upload 1000s of records into a custom entity on model driven Power Apps. I am able to read in text fields, option sets, dates, etc without any issue. However when I try to map lookup fields, I get an error that says "can't resolve the guid for the lookup field:...". I am able to select "Edit in Excel" in an entity where I can manually select the appropriate lookup choice. But i can not copy and paste the item name because it does not recognize it as a GUID. There is too much data to do this and I need a way to complete this in a programmatic way.

I essentially want to relate the Product IDs (500004, 500370, etc) to the POBs (POB-1000, POB-1001, etc), as records that I can connect together in the model driven app.

Error message after mapping fields and importing:

Answer 1

By default, while importing in CRM (aka Model driven Power App), Lookup field will expect either GUID of that record (ex. 78C03F0D-4618-41C6-9089-B5BDB456465A) or Name (Primary field of that entity record, ex. Full name) to resolve the particular record to be associated.

If you want to map another field, you can map it while doing mapping in Import wizard.

How To Set A Lookup Value With Non-Primary Field As Reference