vyos@vyos# set vpn l2tp remote-access extended-scripts
Possible completions:
   on-change            Script to run when PPPoE session interface changed by RADIUS CoA
                        handling
   on-down              Script to run when PPPoE session interface going to terminate
   on-pre-up            Script to run before PPPoE session interface comes up
   on-up                Script to run when PPPoE session interface is completely
                        configured and started