I delved into this a little. A good free option is broadcasting to YouTube Live, however they don't directly accept RTSP feeds (protocol IP cameras use) so you need to convert it to a RTMP feed first. You could try FFmpeg (I didn't have much luck with this) or OBS Studio (had better luck with this but would often stop working after a few days and would need manually restarting).
In the end I ended up paying for a subscription with ipcamlive.com, they take a RTSP feed and give you an embed code which you use to put the live video on a webpage. It just works, and you don't have to run your own server or computer to transcode the video for something like YouTube live.
If you are looking for reliable 24/7 live streaming and want a simple solution I'd go for ipcamlive.com, but if you are just broadcasting for a few hours at a time OBS Studio and YouTube Live is a good option.
