[Solved] powered by surveygizmo appearing on private domain

I am assuming that your question is how to turn the “Powered By SurveyGizmo” tagline off.  You can toggle it off in the Layout section of the Style controls.  See the SurveyGizmo documentation for details on how find it and turn it off – https://help.surveygizmo.com/help/turn-off-powered-by-surveygizmo-logo

Does the logo appear only when you use your private domain?  We would need some more details about your custom link and how it is being used to make a diagnosis.