At all in group

[Anduin2017]

Describe the solution you'd like

When I wanna at everybody in a group I own, I have to I have to at each other.

Describe alternatives you've considered

If I am the owner of one group, I can at @all at once. When the client is calling API, for the ats part, add all members' ID.

Additional context

Nothing.

[hv0905]

What about ating all members when posting at0=all ? If we add all user ids in the group into the form, the form might be too large