After Selecting it fill there required details, there will be 7 fields that you need to fill, One is Protocol input that you already have selected as FTPS.
Location Name: It is used to identify your location as you can add Multiple FTPS backup locations.
Server Host: Its the location of your FTPS for eg ftps.mywebsite.com.
Port: The FTPS port usually the default port is 21.
FTPS Username: Username of your FTPS account.
FTPS Password: Password of your FTPS account.
Backup Location: It's the name of the folder where your files will be saved it requires a relative path.