How to add Thunderbird to Start up applications?

I’m currently running Mate 18.04.1 and I’m trying to add Thunderbird to my start up menu with no success.
How can I set it up so that Thunderbird starts when my computer boots up ?

Thanks,

Bruce

From the Control Center, open Startup Applications, click Add
name: thunderbird
command: /usr/bin/thunderbird
comment: start thunderbird
Save
reboot