Commend a fellow soldier is one of many objectives you'll come across as you explore the Headquarters hub between multiplayer matches in Call of Duty WW2.
It is a social-oriented goal that requires another player to complete, and with the game launching with intermittent server connections - which can sometimes mean the Headquarters is empty - it's proven more difficult than it looks.
How to Commend a fellow soldier in Call of Duty WW2
First, log into multiplayer and enter the Headquarters social space. Right now, this is easier said than done with server issues, but keep trying and you should (hopefully) get in eventually.
To start the specific 'Commend a fellow soldier' challenge in Headquarters, first have access to the social space by playing one match, then complete the first set of challenges that appear (these should involve you visiting specific vendors). Then log in and out of Headquarters to refresh the challenge list, and it should then appear.
Once you have the 'Commend a fellow soldier' challenge appear, you must find another player. This can be a friend or someone random, it doesn't matter. Stand next to them, and press the Square (or X on Xbox) prompt that appears over them when you get close to bring up a menu.
Commend Player is one of the options on this menu. Highlight it and press accept to give the commendation and complete the challenge.
Note you can only give a commendation to a player once, and the challenge is a one-off, giving you 750 XP for doing so.
Out for more advice on COD WW2's multiplayer? It's worth checking out which Division suits you best, then how to unlock the best COD WW2 guns as well as its various Prestige rewards using fast XP methods. If you're still having connectibity problems post-launch meanwhile, our Call of Duty WW2 server issues delves into error codes and other troubleshooting tips, and finally we can also help you tick off the Commend a soldier challenge in Headquarters, too.
How to Commend a fellow soldier with empty Headquarters
A problem is at launch Headquarters can be devoid of other players, which is due to server issues or maintenance:
It's solo for now due to maintenance. However, you can invite friends to your HQ.— Sledgehammer Games (@SHGames) November 4, 2017
However, as mentioned there by developer Sledgehammer Games, there is a workaround. Though the space is empty, you can invite another player to your Headquarters to 'populate' it with one other player, allowing you to complete the challenge.
To do this, press the pause or Options button to visit the menu, then go along the top menu navigator to Social. This is where you friends list is, allowing you to invite other players on your friends list. Send them an invite, and when they accept, they should appear with you.
We attempted this and had a few disconnects - again, likely due to server issues - but be persistent or try again at another time and it should work.
If you are struggling with this method, then waiting a few days until server issues are hopefully ironed out so random players appear in your Headquarters might be the best way to complete this challenge.