Custom and extension parameters often are not required. If your tool does not recommend entering a value here, and you're not familiar with the available parameters, you should leave this field empty.
Send these additional custom parameters:
One per line, in the format: name=value
Check with your tool provider to find out which custom parameters are expected and what they do.
Custom parameter names must start with "custom_"
Extension parameter names must start with "ext_"
If the name or value includes an equals sign (=), enter it as %3D to avoid issues