How can I publish a file to the Figma Community with a prototype preview?

This is my first time publishing to the Figma Community, and I want it to be previewable as a prototype, but the option is disabled. How can I fix this?

Thank you!

Screen Shot 2566-09-10 at 01.31.07

Was facing the same issue and saw this thread unanswered. I’ve figured out that you must put the prototype on the first page to be able to make it as the preview.

You can also republish what previously set preview as a file to prototype (just re-published mine https://www.figma.com/community/file/1375786704431017390/multiselect-conditionals-prototyping-with-variables).

Hope this helps others.