Change parameter mvbox move

Tell me how can I change this parameter? otherwise adding relay doesn’t work.

    "mdns_enabled": "1",
    "media_quality": "0",
    "messages_in_contact_requests": "0",
    "mvbox_move": "1",
    "num_cpus": "4",
    "number_of_chat_messages": "6984",
    "number_of_chats": "14",
    "number_of_contacts": "32",

can this be changed in the application or chatmail settings?