As of right now, only appeals with received gifts in NXT allow you to go to the appeal record in NXT. It would be useful to access the appeal for even those without a gift to see the additional appeal information. ie. attaching the actual collateral.
Make sure the appeal is associated with a campaign (if it is a solicitation, it always is anyway). I'm able to navigate to the Appeal Record through the associated Campaign Record & add Attachments.
I created a similiar Idea RENXT-I-1082. I figured out the following workaround: