namespace Firebase not found (new download)

[SrirachaSource]

I'm updating Firebase in Unity project (it's been at least 2 years) and having lots of trouble. I downloaded this example and it doesn't even build in Unity 2017.4 getting: error CS0246: The type or namespace name 'Firebase' could not be found. Are you missing an assembly reference?

I'm getting this same type of error in my project with the new firebase, it's like the Editor scripts are missing.

[AnandGameDev]

try Dotnet 3