curl --location --request POST '43.139.194.209:8088http:://127.0.0.1/course/joinCourse?username=undefined&InvitationCode=undefined'{
"result": {
"join_url": "//127.0.0.0",
"joinable": true
},
"errcode": 0,
"success": true,
"errmsg": "ok",
"request_id": "2zw2h7s074d1"
}