SOLVED How to Add User to Groups

I’m new to Calculate and Gentoo. I’m looking to add my user to groups. I have hunted around system settings to find how to preform this action. Every search that I do on the web resorts me to kuser. I must have missed certain groups on install.

Thanks

Dell OptiPlex 980
4 x Intel core i5 1st Generation
CPU 660 @ 3.33GHz, 8 GiB RAM

If this is still relevant

As root

usermod -aG <user> <group>

https://www.howtogeek.com/50787/add-a-user-to-a-group-or-second-group-on-linux/

Kuser was nice kde4 based user management app, in which I could change groups of certain user. Plasma5 new app is crippled, and very basic. I don’t know about other gui apps.

Thank you a lot. Works for me. =-)