Please post the complete specs as asked in https://retropie.org.uk/forum/topic/3/read-this-first.

What the error message you're getting when the installation fails ?

@grocket12 The repository used by RasPI OS automatically redirects apt based on your location to the closest Rasbian repository mirror. If that mirror doesn't work for you, you can manually change the URL in /etc/apt/sources.list to one of official Raspbian mirror servers - https://www.raspbian.org/RaspbianMirrors.