it seems you should be using debian or distros based on it. ubuntu, as far as i know, uses apt as a mirror to snap, so as long as the tutorials youre following letter for letter arent too recent, you really should be using debian for actual apt packages, since ubuntu used those a couple of years ago.
you can also use fedora or arch, but it seems you dont want to check what package youre downloading at all, and just want to follow tutorials blindly.