Add the Elytra Fly permission to your /is permissions menu, this is an addon for the popular skyblock plugin SuperiorSkyblock2. You can add the permission to the menu by adding a new permission in the permissions.yml gui file. Naming it "ELYTRA_FLY" will get the permission. You can also assign it to a role by adding "ELYTRA_FLY" under one of the permissions per role in the ssb2 config.yml file. (See images below, the first one beeing the "permissions.yml" gui menu, the second one the "config.yml")