Automatic Follow Up Email to Learners 3 Months After Completion of Survey

Hi there,
I hope everyone is well. I need to send an email out automatically to all my learners 3 months after they finish the survey with a follow up survey. They will finish the survey on different dates so I can not do this in one mass email. How do I do this? The email trigger option would work perfectly for this but it only allows me to send an email 28 days out. Is there a way this can be done 3 months out or length of time can be customized?
I did find this when I did a general search but the link to the solution offered in the follow link is broken (create an email list trigger then "create an action to run a web service that uses the Qualtrics API" ): https://www.qualtrics.com/community/discussion/1841/how-to-send-out-email-trigger-for-a-follow-up-study-5-months-after
I can't imagine I am the only one who wants to do this so I hoping for a solution.
Any direction you could provide would be greatly appreciated.
Take care,
Rima