If it is not possible to provide an email address of the survey participant, or you want the respondent to directly fill in a survey during a visit on site - either have the participant complete the phases and steps in Castor, or you can use the survey module without sending email invitations to the participant.
You still have to create the survey invitations for the record (patient) in Castor EDC. Since an email is required to do this, you can enter your own email address. Just select 'decide later' when asked to set the time of sending so you do not actually receive the email invitation.
When the patient is on site, e.g. during a visit, you can simply open the survey. This is done by clicking on the cogwheel next to a survey invitation and selecting option 'Open in new window'. You can request that the patient complete the questionnaire. The survey is a simple url link, so you can close the window/tab where you were logged in.