If your current podcast hosting does not allow you to redirect your podcast feed to RSS.com you have to manually change the podcast feed URL in Spotify for Podcasters.
1. Login to https://podcasters.spotify.com/, then click on your show.
2. Click on "Details".
3. Click on "Update".
4. Paste in your show's new RSS Feed URL, then click on "Next."
5. Confirm your hosting provider is correct, and that everything looks good.