How to create group

Hi ngocchaunguyen ,

With this being a Teams Forum, I trust that you are referring to creating a Team, which will of course behind the scenes create a Microsoft 365 group as part of the process. 

So within the Teams Client, providing it has not been disabled within your Org, towards the bottom left you should see the option of Join/Create Team.

https://docs.microsoft.com/en-us/MicrosoftTeams/get-started-with-teams-create-your-first-teams-and-channels

There are of course a whole host of programmatical ways to do this also.

Thanks

Henry