Retrict file column format to PDF only

Is there a way to restrict file columns to upload PDF only?

I’ve tried data validation expression RIGHT(TEXT([_THIS]),3)=“pdf” (I know it was a long shot), but doesn’t work.

I can create a Validation Virtual Collumn IF(RIGHT(TEXT([File_column]),3)=“pdf”,True,False) or WORKFLOW with similar condition and somehow notify the user AFTER save the record, but I haven’t found a way to prevent it.