When clicking on the Add button in the Custom Directory List Manager in Directory Submitter you will see the following options as in the image below.
This is Step #1 in the Custom Directory List Manager wizard, here you should enter the url and name of the directory you want to add into the custom directory database.
Note: You can alter the url for the directory in Step #2 if you need to.
Once you have entered the url and name for the directory, click the Next > button.