I want to try use testflight for my app beta version, anyone know the step to do this.
And also, certification and provision use existing development key or need to generate a new certificate and provision..
You can use old certification with new distribution provision. You need to add UDID of all test devices too. Download release ipa file from hosted builder. Upload ipa file to Testflight, share the generated link to all testers to install your app.