How to roll back to packages.config from PackageReference in ASP.NET Core 3.1 in Visual Studio 2019 [closed]

I am working in ASP.NET Core 3.1 where I want to have packages folder with packages.config file. I tried with these links

• How to roll back to packages.config
• Switch back to packages.config

I changed the Visual Studio 2019 Tools settings

Tools > Options > NuGet Package Manager > General > Default package management format is set to Packages.config

Before reopening, I had clear the NuGet cache:

Tools Menu -> Nuget Package Manager -> Package Manager Settings -> Clear All NuGet cache(s)

Steps followed:

1. Removed all PackageReference elements out of the project file.
2. In VS 2019 :Tools>Options>NuGet Package Manager>General>Default package
   management format is set to Packages.config
3. Cleared NuGet Cache: Tools Menu -> Nuget Package Manager -> Package Manager
   Settings -> Clear All NuGet cache(s)
4. Added an "empty" packages.config file to the project (without individual
   elements)
5. Manually trying to install the nuget pakages

packages.config file created as:

<?xml version="1.0" encoding="utf-8"?><packages><!--<package id="Microsoft.VisualStudio.SlowCheetah" version="3.2.26" targetFramework="net472" developmentDependency="true" />--></packages>

Still packages are adding to my xxx.proj file not to the packages.config filewhen i installed the packages manually . This is my requirement for azuredevops buildpipeline as our azure devops server is not downloading thepackages if i use PackageReference(Offline). Any advice on can we roll backto packages.config from PackageReference in ASP.NET Core 3.1?