after completing the development of an expo app, I want to share it with friends who can check it by QR code or link to a live server. How can I do it?
If you are using the Expo Managed workflow, you can share your application with Expo Go. In this case, you don't need to publish in any store. Follow the instructions from section Share a development build with your team. With this, you can use the Expo Dashboard to deploy a project and share the URL or the QR Code to scan by the Expo Go App. I created an Expo project to share with a link that contains the QR code to run on Expo Go.
Note: To see the Expo application you must to install Expo Go.