I would suggest PostHog. They do have 1 Million/month event free tier and can be self hosted. Love their offering and been using it for a year now without any problem.
Last time I looked at PostHog, their documentation for self-hosting had the tone that you’d be an idiot to use it for anything other than a small experiment and that it would fall over for any production workloads. It actively discouraged me from going any further with PostHog.
