If you want a solution that works on every Linux distribution, you can install Docker and run i2pd (a high-performance C++ variant of I2P) as a container. The Docker image is: purplei2p/i2pd Or…, even easier, you can run i2pd via flatpak (also works on every distro). See here: https://i2pd.readthedocs.io/en/latest/user-guide/install/ Hope this helps 🙂
It seems i2pd is a healthy project, judging by the frequency of updates to the docker image as well as the github releases going back 10 years.