Here is links to all custom maps in servers, and to play, player need to download map, unzip .vpk file in addon folder of game, start game and play. Command to change map instantly is by typing !chmap or /chmap in game chat.
more info and updates of some maps are here: [You must be registered and logged in to see this link.]
in meantime some are updated, some links broken, some new versions are broken and old not exist nowhere, so some links i provide in my google drive, links are all in steam group links Exsample: Cold case 2018 is broken, use from link cold case 2017 Crash bandicot: return of dr cortex is broken, crash on map 2 all time without plugins Other seems to work