@gikidolooking at the error, I expect IdAudit to be a record.
Is the RecId GUID field available in the record? If so, could you give this a try:
LookUp('Cheklist';Gallery1_3.Selected.'RecId '= IdAudit.'RecId' ; Bronze)
If your ID field within IdAudit has a different name, use this structure: IdAudit.IdFieldName.
Alternatively, if the Selected record is the same as IdAudit, you could try comparing records:
LookUp('Cheklist';Gallery1_3.Selected = IdAudit ; Bronze)
I hope this helps!