Installing SpecFlow headlessly

I'm trying to generate a steps file in a headless environment with SpecFlow 3.9.74 installed. The following results in an error that "Tools" and "UnitTestProvider" namespaces do not exist and I couldn't find documentation about it, so seeking help:

using System;
using SpecFlow.Tools.MsBuild.Generation;
using SpecFlow.UnitTestProvider;

namespace StepDefinitionGenerator
{
    class Program
    {
        static void Main(string[] args)
        {
            var generator = new SpecFlowProjectValidator("./CucumberApp.csproj");

            generator.GenerateTestFile("./Features/cucumber.feature", "./Steps/Steps.cs");
        }
    }
}