Locking this topic, for reference use the forum search and you would've found the solution.
-> https://forum.plutonium.pw/topic/9341/how-to-load-mods-custom-maps-on-your-client
Request support for the Plutonium T4 client, please wait at-least 1 day for a reply, it can get busy. The community is free to try to help in any thread.