Steam is an online gaming platform that, among other things, also allows players to interact with each other. You can add friends to your Steam network, as long as you know their username or can have access to their profile.
Steps
Method 1 of 2: Add By Username
Step 1. Launch Steam on your computer
Step 2. Click on "View Friends" in the lower right corner of Steam
A pop-up window will open containing a list of all your friends.
If you don't see "View Friends", make the pop-up window larger. Sometimes your display or computer settings may prevent you from seeing all the text
Step 3. Click on "Add a Friend", located in the lower left corner of the pop-up window
Step 4. Enter your friend's username in the text box, then click "Next"
This user will be added to your Steam friends list.
Alternatively, you can click "View Recently Played Users" or "Search Steam Community Members" to find friends or particular users
Method 2 of 2: Add Via Profile
Step 1. Launch Steam on your computer
Step 2. Open the profile of the user you want to add to your friends list
You can search for the name of a specific user, or click on "Groups" to find a user you have interacted with recently
Step 3. Click on "Add to your friends list" located in the right sidebar of the profile page
This user will be added to your Steam friends list.