Local nuget package A is added into B, but B doesn't see it

2 projects: MyProj.A and MyProj.B.

MyProj.A is built as NuGet package and added to MyProj.B.

MyProj.A is examined with Nuget Package Explorer and I see all types inside but MyProj.B sees nothing, even MyProj.B itself.

MyProj.A structure:

MyProj.A.csproj:

<Project Sdk="Microsoft.NET.Sdk"><PropertyGroup><TargetFrameworks>netstandard2.0;net452</TargetFrameworks></PropertyGroup></Project>

MyProj.A.nuspec:

<?xml version="1.0"?><package ><metadata><id>MyProj.A</id><version>1.0.0</version><authors>MyProj</authors><owners>MyProj</owners><requireLicenseAcceptance>false</requireLicenseAcceptance><copyright>Copyright @ 2023</copyright><description>MyProj A.</description></metadata></package>

Class1.cs:

namespace MyProj.A{    public class Class1    {        public int Prop { get; set; }    }}

NuGet Package Explorer view:

MyProj.B view: