Getting unauthorized response when previewing draft content

Silverstripe Version: 5.3.2

Question:

When a user preview content in draft I am receiving a 403 response and a login page intead of the preview.

If I visit the same page as an admin I can see the content.

Do I need to modify a function like canView to set correct permissions?

Not sure with Silverstripe 5, but on previous versions you could achieve the same result by just using the back end: ensure all users you want to give draft access are in a group with the VIEW_DRAFT_CONTENT privilege enabled.