At my wits end with potty training

My son is obviously 3 and still not trained. He has zero interest in trying. He refuses to sit on the potty or toilet and constantly moans to be put in a nappy. Its now getting to me mentally cause some people are not kind that we've still not cracked it. We've been trying for over a year and nothing works. I've tried bribes, bare hum but he refused to not have pants on, sitting him on potty every 20 minutes for him to have a meltdown and not wee, to then wet himself a minute or so later. Its really upsetting for us all and I feel like I've failed him 😔