We recommended using an additional plugin called Import Users from CSV.
how to use it you only need to install and activate it then you can access it on admin panel > User > Import Users from CSV.
You can see the template in blue writing or you can take our format here
On the import template you should replace the header table with "user_active" and fill with number 1 on the table so that the user you enter can be activated immediately (column H).
when it's finished you can import it.