MSSQL active users by month

I would like to know the number of active users by month, I use MSSQL 2017.

I have an AuditLog table like:

- UserID: int
- DateTime: datetime
- AuditType: int

UserID  DateTime     AuditType
------------------------------
1       2022-01-01   1
1       2022-01-15   4
1       2022-02-20   3
2       2022-01-10   8
2       2022-03-10   1
3       2022-03-20   1

If someone has at least one entry in a given month then he/she is treated as active.
I would like to have a result like:

Date     Count
2022-01  2
2022-02  1
2022-03  2

>Solution :

I think you can combine the function Month(datetime) in the GROUP BY with the Count function SELECT COUNT(UserID)