In ACT:
\install file_pathname [[schemaname/]installed_filename]
In ODBC:
INSTALL FILE 'file_pathname' [[schemaname/]'installed_filename']
In ODBC only, if the schemaname contains mixed case letters or spaces, you must surround the schemaname only in double-quotes.
Once you have installed a function, you must set users' privileges to run it as explained in GRANT EXECUTE on a function.
If your \install attempt fails, ask the schema's administrator to grant you the right permissions. See GRANT INSTALL FILE and GRANT CREATE FUNCTION on a schema.