A small C# tool to create many websites at once in directadmin. There is no check of any kind, so it works if you give it proper url, login and password. Beware, any error in credentials, may result in blacklisting your local IP on the server.
If you want the exe only, here it is : https://github.com/bokanist/DirectAdmin_Bulk_Website_Create/blob/master/DirectAdminCreateSites/bin/Release/DirectAdminCreateSites.exe?raw=true