You cannot use the output from an expression as input to another expression. If you manually add the output column name to the expression, you might get unexpected results.
Select functions, columns, variables, and operators from the point-and-click interface to minimize errors when you build expressions.
If the data masking rule is configured for repeatable masking, specify the storage table in the data masking plan. If the storage table does not exist, the data masking operation fails.