I didn't asked if you tested what you did post. I asked if you tried anything else before asking to be fed the answer. If you did it would be nice to include those other attempts.
David J.
It's already working:
INSERT INTO junk.wm_260_billables2 (account_id, code, info) SELECT account_id, 'test_' || uuid_generate_v4(), info FROM junk.wm_260_billables1;
BUT.. I'm getting a very long UUID - Would like some smaller