Quartz and the packages around it come from NuGet:

dotnet add package Quartz

That one package is the whole install for a scheduler: dependency injection, hosting, the health check and System.Text.Json serialization are all in it. The quick start lists the optional packages and what each is for.

Each GitHub release also has a Quartz.NET-<version>.zip with the source, the compiled binaries, the example projects and the database/ directory: the table-creation script and the migrations for every supported database. The scripts are also in the repository, and schema changes describes each migration.