Please find below steps on how to enable the license requirement when packaging your IP via IP Packager.
1. In your top-level RTL file, add the license string that is quoted with an asterisk and inside parentheses before the "module" syntax.
Example:
(*LSC_IP_SC_HT_CITROBITS_MC*) module counter ();
....
...
..
.
endmodule
2. Add the rtl file in the IP packager and make sure to enable the Encryption checkbox.