Specified primary key type is not number

I am attempting to create new collections (i.e tables) via CSV upload into Jet Tables. The data in the csv files already have lowercase varchar primary keys and foreign keys.
The import UI displays an error saying the specified primary key has to be a number. Is this a bug? Since Jet Tables are built on top of a Postgresql backend I assumed varchar keys would be allowed.

Hello @Charles_Walsh
Yes, the ID must be a numeric value when you import data into Jet tables.