How to deal with library versions in .NET Standard?

Question

.NET

I am creating a project on .NET Framework v 4.6.1.
I create a .NET Standard core library for it. When creating a library, it was suggested to choose a version of the framework. As a result, a project of a certain version of Standard was created. But at startup, it turned out that the version of the System.Net.Http assembly did not match. I had to downgrade .NET Standard (well, not really. I googled and downgraded and it worked).
Now I installed the Newtonsoft.Json package to this Nuget library and at startup I catch an exception that this assembly of version 10.0.0 was not found. wtf??? Why is this version searched for if version 10.0.3 is installed? I wanted to downgrade, but there is no version 10.0.0 at all. There is 10.0.1 (it does not fit) and below is already 9.
Help me figure out all these dependencies and versions. The general meaning would at least catch.