i missed understanding Default Unit of Measure at first i used CM as UOM but after i understand how it works i want to change all items from CM to Piece
what i tried to export all item data in csv file and change all CM to Piece then upload it and try to update records
but i get this error message
Default Unit of Measure for Variant 'Piece' must be same as in Template 'CM'
@fatheyabdelslam you can rename CM to Piece, and while renaming, pick the option “Merge with existing”
It may solve you issue.
Another approach, is change the Unit of the Template, and It may will change into the variants.