Player does not have permission to mount/umount

Error: User {username} lacks permission to update the World setting mount-up.ride-links
    at Function._onUpdate (/root/foundry/resources/app/dist/database/documents/settings.js:1:1467)
    at Function._onModifyDocument (/root/foundry/resources/app/dist/database/odm/document.js:1:4946)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async Socket.handleEvent (/root/foundry/resources/app/dist/sockets.js:1:1942)

How can I give my players permission to mount / unmount?