Via your site link to the messenger. Wherever it is. :)
When we add a menu builder you’d be able to add it to launch bar.
But we currently can't download it correct, until further notice?
Apps are available for UNA.IO site - via the App Store. We are basically making them available for testing on our site first. Apps will be available as a product, (so you can create apps for your site) in a couple of weeks.