Open Keychain Access on your MAC System
Create a Certificate (Keychain Acces -> Certificate Assistant -> Create a Certificate)
Go to Category (Left Pane of your Keychain Access)
Click on My certificates (If needed Please Close the Keychain and Re-open it)
Please check whether your certificate is there or not.
For future use Please export that certificate from keychain.
Launch Xcode (if already opened then restart Xcode)
Open your Project
Go to your Project Build Setting and Find Code Signing
Update the code signing certificate that you generated.
Run the App by selecting the IOS device option.