Hi @anon93552306, thanks for reaching out! As it stands, it’s currently not possible to share a View only access of an Asana Board with external users that don’t have Asana accounts.
We already have a thread requesting this feature in List view: View only access to projects/tasks for clients so I’ve gone ahead and move your post to the #productfeedback catgeory and updated the title to make it more specific to Board view.
We hope to share exciting news about this topic soon! 
Stay tune and Follow our News category to keep up to date with what’s new in Asana! 📨