Hi @Lydia, welcome to DevKinsta!
Is the DevKinsta site based on a Live environment or Staging from MyKinsta?
It sounds like your blog might be a reverse proxy similar to this one
To avoid making configuration changes in DevKinsta, you’ll need to first convert the site to a non-reverse proxy setup. The best course would be to create a Staging version of the site in MyKinsta, have that converted to a normal structure then copy that version of the site to DevKinsta. Our support team would be able to help you with updating the configuration on the Staging environment.