Copy PackageReferences to output directory

I have a netstandard2.1 classlib project, and I noticed that

PackageReference

PackageReference

s are not copied to the output directory.
I have tried

Private="true"

Private="true"

and even

CopyToOutputDirectory="always"

CopyToOutputDirectory="always"

, but both had no effect.
Is there any way to configure msbuild to copy packages to the output directory?