Click on the rank you'd like to enrol the player onto
Hover over the row you'd like to add the player to and left click. You'll then be shown a dialog to appoint a player.
Click on "Appoint a Player" to access the player selector
The player selector will be shown along the right hand side of the screen. From here you can search for members and select which player you'd like to enrol. Once you've made your selection, click on the "Appoint" button at the top right.
Player will be added to the roster
And that's it, the page will refresh and you'll now see the player assigned to that specific rank/callsign. If you have provided a roster announcement channel in Discord, FiveRoster will also post this appointment in that channel.
