问Im的小程序demo无法正确加入群组？

[group_open_http_svc][apply_join_group]failed:

request url:

https://webim.tim.qq.com/v4/group_open_http_svc/apply_join_group?websdkappid=537048168&v=1.7.0&tinyid=144115211257718019&a2=6aae5415e3d8af67e57eefb81ba47181b41b159a994a0be24738ee1d7cf821de3a471bcb90bd2c7d1d0c82d4ec545350ba30cfeccbc530cb51aa242afb6480875280d381a921a770&contenttype=json&sdkappid=1400037025&accounttype=884&apn=1&reqtime=1531373764

request body:

{"GroupId":"@TGS#aWTBZTDFW"}

response:

{"ActionStatus":"FAIL","ErrorCode":10010,"ErrorInfo":"this group does not exist"}