Press Tab, or whatever you have bound your console key to and type
example = enablecheats pass123
From here you can enter commands.
Whitelisting an Admin
This allows you to use commands without needing to login as Admin.
Create a file in the directory \ShooterGame\Saved\ called AllowedCheaterSteamIDs.txt
It should look like this \ShooterGame\Saved\AllowedCheaterSteamIDs.txt
From here, list on each line the Steam64 ID's you wish to authorize for cheat commands, these users will be able to cheat without logging in as Admin.