@hellomiakoda run sudo visudo to edit your sudoers file (/etc/sudoers), it's not recommended to edit it in any other way, change the editor it uses with EDITOR=nano sudo -E visudo (replace nano with your favorite)
@hellomiakoda hm, I've only ever added commands to it to allow running them with sudo without entering a password, if you can't see anything it's probably somewhere else, sorry