Inviting users requires the permission INVITE_USERS or higher.

curl --location --request PATCH 'https://sux.chatsight.ai/api/users' \
--header 'Authorization: Bearer <API_KEY>' \
--header 'Content-Type: application/json' \
--data-raw '{
    "patches":[
        {
            "key":"@user/invite",
            "target":<USER_TARGET>
        }
    ]
}'

What can I put for <USER_TARGET> ?

Target can be a fully qualified email of a user OR a fully qualified User ID.