You must first create a main account in ACP, after logging in to this account you can create any number of accounts on the game server.
Link to ACP
https://account.badlands.online
You also need a clean Interlude client + our server patch and an updater
Links:
patch:
https://mega.nz/file/gWsH0DSZ#Wjz3A9wFJm0Zbj0q2ECbGSbHVBIQVhaKpzSgZijZldQ
or
https://drive.google.com/file/d/1fehLCXIRoZfPHrK-OCpCLgQpB_yed6CY/view?usp=sharing
Updater:
https://badlands.online/upd/Badlands_updater.zip