using an external display device on ipad pro 11in

I recently purchased an LG UltraWide 34WP65G-B 34 Inch Full HD 5ms 75Hz Monitor, USB Type C, AMD Freesync and I am currently attempting to use this device's onscreen controls to set it up to display wide screen video from an ipad pro 2018 11in using ipados 15.6. I would like to hear from other ipad users of on-screen controls on an LG ultrawide connected to the ipad pro via HDMI cable. I am particularly interested in the detailed operating instruction set for the onscreen adjustment of the display device and where I can obtain a reference copy of these instructions.