Restream is great. I used their service when I was still streaming across legacy sites. I now use zapstream's free restreaming to push the stream to Trovo and to YT to store past streams for free.

I used restream too for one month but found it too costly. In the end I settled with cloudflare as I could point that to every RTMP server without worry and the quality and bandwidth speeds were top notch. Really cheap too at like $5 a month instead of Restream being $15-30! My want to go solution is to find a github repo with it's own RTMP hosting solution that might work on an old PC or a Raspi4!