To send a game request to a friend, you will need to select Play from the main screen and then Classic. Once there, to the right of the "Random" option, you can choose the friend you want to play with by swiping the screen. You can also search for friends in the search engine.
You can also search for the user from Profile (by pressing your avatar or profile photo) > Following. Once you find it, you must select Play, to the right, and the game will begin. 🙌
How can I invite friends to play Trivia?
How can I add a user to my friends list?