how to change admin username on linux server

I installed motionEye Version | 0.42.1 on linux ubuntu server, I want to change adminn user name, when I open /etc/motioneye/motioneye.conf there is no row mentions admin user name, so I added it like this : # @admin_username myadminusername and restarted using service motioneye restart but it didn't work, I tried only @admin_username myadminusername , restarted, then only admin_username myadminusername and restarted , and even with no space at the beginn , all didn't work