I want to test my Xcode project at my device (iPhone 5s, IOS 10.2) for free (without paying 99$). I don't want send my projects to App Store. I went to developer.apple.com and created Apple ID. Then I opened Xcode, created a new project, went to Preferences and Added my created Apple ID. But Provisioning Profile doesn't created. In "Keychain Access" when I tab to certificate, I see the red inscription: "This certificate was signed by an unknown Bureau". How can I solve this question? Thanks a lot!
I believe you are missing Apple's Worldwide Developer Relations Certificate Authority (WWDRCA), located here. Download and install that on your Mac and give it another shot.