Double-click it or click the arrow to move it to the list on the right. Click Confirm Changes at the bottom.
Navigate to the mod page for the "Range Rover Startech 2018." Download File Range-Rover-Startech2018.scs
Troubleshoot why the mod in your Mod Manager. Double-click it or click the arrow to move
Click the download link (often hosted on sites like ShareMods or ModsBase). Download File Range-Rover-Startech2018.scs
On the Profile Selection screen, click on the (the icon looks like a folder with a gear). Find "Range Rover Startech 2018" in the list on the left.