Database Engine 20 does not perform implicit conversion on input arguments to UDFs or external stored procedures (external routines). Arguments do not have to be exact matches to the parameter types, but must be compatible. For example, you can pass a SMALLINT argument to an external routine that expects an INTEGER argument because SMALLINT and INTEGER are compatible. To pass a DATE type argument to an external routine that expects an INTEGER argument, you must explicitly cast the DATE type to an INTEGER type.
There are SQL functions and operators that require arguments that are exact matches to the parameter types. See the documentation for the specific function or operator.