To invite friends to join you in Deadlock, navigate to the main menu and locate the 'Invite Your Friends' button at the bottom right corner of the screen. Clicking this button will display a list of your Steam friends, indicating who can be invited, who has already been invited, and who currently has access to the game. Select the desired friend and send the invitation; please note that it may take up to a few hours for the invite to be processed and received. [Source: https://www.ign.com/wikis/deadlock/How_to_Send_Deadlock_Invites_to_Friends]
Deadlock's invitation system allows players to expand the playtest community by inviting friends directly from the game's interface. After accessing the 'Invite Your Friends' option in the main menu, you can select friends to join the playtest. It's important to be patient, as the invitation process can take some time; delays of up to three hours have been reported. [Source: https://steamcommunity.com/discussions/forum/1/4511003785958903445/]
When inviting friends to Deadlock, ensure that your Steam client is up to date to avoid potential issues. After sending an invitation via the 'Invite Your Friends' button in the main menu, communicate with your friend to confirm receipt, keeping in mind that there may be a delay. If the invitation does not arrive within a few hours, consider resending it or checking for any connectivity problems. [Source: https://www.thegamer.com/deadlock-playtest-how-to-get-send-invites/]