How to get a loved one to treatment

Hi. I'm writing here because it's been hard to find information about what to do when someone you love is refusing treatment. My loved one (23male) suffers from schizophrenia, he's had it since being 18, and has been taking injections to manage his symptoms. He managed to start university and be top of his class but dropped out recently on his last semester because he hasn't been wanting to go to his psychiatrist to take his injections.

He ran away one day, was found the night of that day; was persuaded to go to his psychiatrist but he refused to go in once it was his turn; and was forcefully taken to a mental institution 2 days later. It was a very violent and traumatic event. Completely out of line. A violation of his rights and human dignity. He was at someone's house, wasn't being violent, there was no need to do such a thing. But my family was just worried and desperate because he is deteriorating, and refusing treatment.

He didn't end up getting admitted because he tested positive for COVID19 on a rapid test. The next day he tested negative on an actual test. I truly believe the COVID19 thing was a blessing in disguise to stop him from being admitted against his will.

I'm not in favor of forceful medication. I will protect him from getting admitted against his will. But I'm really lost on how to get him to accept treatment. He really is deteriorating with every passing day, even though he can hold conversations and seem normal, we know his brain is changing even tho we can't see it. I want to be respectful of his autonomy and his rights, I want to act in an empathetic way, I just don't know what to do. He doesn't want to go to the doctor, or to see a therapist, he doesn't even want to talk about his illness at all. How do I proceed? Any thoughts? Has anyone been through this?