How to install "com.unity.Mono.nuget.mono-cecil" package to Unity project

I was working on starting some work with Photon engine, and ne dependancy was the unity package version of Cecil. There is an API reference to it, but I cannot find it in the package manager or anywhere online. Can someone help me figure this out, I have only really used unity for around 3 years and I am very new to this engine.

Edit: I am using Unity v2021.1.5, if that is relevant

Thanks!

I think you are rather referring to com.unity.nuget.mono-cecil.

As this is a package link you (try to) can install it into your project even if it is not appearing in the Package Manager.

In the Package Manager Window simply click the ✚ → Add package from git URL ... and enter

com.unity.nuget.mono-cecil

and then hit Add.

Update

I don't remember which exact version but by now they actually separated this into individual options, among them the mentioned Install package from GIT URL and for this case specifically Install package by name. For the above you would now accordingly rather go through the latter instead of GIT URL.