You cannot grant this privilege to yourself since grantor and grantee cannot be the same. You can let the user who is already granted the EXECUTE privilege with grant option, e.g., SYSTEM, grant this privilege to you.
For example, open the security folder under SYSTEM -> Users -> double click the user you want to grant -> Object Privileges -> Add -> search the privilege -> deploy to grant the privilege
Or you can run SQL statement to do the same thing.