You can achieve this using custom variables and response criteria-based notifications. Here’s a simplified process:

1. Capture Emails: Use the email question to collect two email addresses. Assign the first email to Custom Variable 1 and the second to Custom Variable 2 using "Update Variable" logic. Refer screenshot: https://prnt.sc/djOoiIU8Q6d9

2. Create Notification: Go to Survey > Edit > Settings > New Notification. Refer screenshot: https://prnt.sc/AYNHVkOGjSuu

3. Set criteria, enable "Email Respondent," and add the custom variable tags in the ""To"" field. Customize the thank-you email text and save. Refer screenshot: https://prnt.sc/tsz_7tObRYGn

For detailed guidance follow these helpfiles:

https://www.questionpro.com/help/setting-action-alerts.html

https://www.questionpro.com/help/creating-and-managing-criteria.html

https://www.questionpro.com/help/custom-variables.html

https://www.questionpro.com/help/udpate-custom-variables.html