Payment gateway not showing in Whitelisted Payment Gateways section

Hi there,
I use the Zip Payment Gateway and as the payment side of it handled by Zip I would like to add it to the Whitelisted Payment Gateways section in the settings.
Unfortunately it’s not showing as an option.

There is a blank option, and I’m wondering if this is Zip, but it’s unable to pull the gateway name perhaps?

Is there a way I can confirm which gateway is listed as the blank one, and am I safe to use the blank gateway on the assumption it’s Zip?

Thanks for your help!
JP