@phil, do you have any updates about this regarding Gatsby? Sharable previews have never worked, either for my Nextjs or Gatsby websites - but a client started asking about them so need to find a solution.
Do you have an example Gatsby project where the sharable previews work?
Hey @kb1995, sorry for the delayed response - my mistake! Shareable links are supported in Gatsby as normal, but there are some parameters around its usage (this is for previews in general, not just for Gatsby).
If using Chrome, previews will not work in Incognito browsers
Chrome blocks cross-site cookies which is required for previews to work. The Prismic toolbar sets a cookie on the prismic.io domain which is then read on your deployed site. Previews are only activated on your site if that cookie is present and readable.
This means share links will not work in Incognito browsers for the same reason. To test if share links work, copy the link, sign out of Prismic, then open the link in a normal browser. It should load.