PM> dotnet add package Flowcourier.Umbraco
Alternatively, you can also find and install the NuGet package via the NuGet Package Manager GUI. Search for Flowcourier.Analytics in Nuget.Org.
Upgrading
Flowcourier Analytics uses standard Nuget.Org updating process. Basically remove the old package and install new package. See Microsoft documentation for more information. https://learn.microsoft.com/en-us/nuget/consume-packages/reinstalling-and-updating-packages
Install License
Once you have purchased a license you can install it by dropping the license file directly into your sites umbraco\Licenses folder. Flowcourier will automatically scan this directory for any valid licenses.