Until this is provided by Asana, a workaround is to use my:
One of the main purposes I had when creating this was to enable those who love to use Asana to still work in Asana when working with others who are not themselves Asana users.
Hi everyone, I’m excited to announce that we are rolling out a new feature that allows you to share your projects with read-only links! This feature will be available on Timeline and Calendar view soon, see more details in the announcement below: