@David-Healey Absolutely
Here's how I found the code singing setting :

• In xcode click onto the project (blue icon)
  

• then go into Build Settings
  

• search for "code sign" in the search bar (top right)

• click on the option for code signing identity
  
  -select other
  

• delete the dash and press enter
  And that should do the trick !

@David-Healey Nevermind, I found the settings for codesigning and before you used to be able to select don't code sign in code signing identity but now you need to select other and then leave it blanc, it now seems to work! I'll watch the end of your video now to see how to install the release version, it might be mentionned in the video but do you delete the debug version once you have the release version ?
Thanks for your time and help anyway, I'm happy it ended up working!