How do I set up a "line replication" shortcut in Visual Studio for Mac?

"Probably, I don't think there is anything that can be done only by installing and setting it up now."

As stated in the answer to the reference article, the original version of VisualStudio for Windows has the function of replicating lines, so you can assign a shortcut.
Can I use Ctrl+Shift+D for row replication in VisualStudio?

4. Enter CTRL+SHIFT+D in Common Edit.Duplicate, Scope text editor, and CTRL+SHIFT+D in Shortcut to close

Default Visual Studio Keyboard Shortcuts
Edit

Edit.Duplicate Ctrl + D

Default Keyboard Shortcuts for Visual Studio for Mac
Edit
Default keyboard shortcuts in Visual Studio for Mac
Edit

There is no duplicate item in the editing function on both Japanese and English pages of the Mac version.

The macro functionality that can be replaced has been removed in VisualStudio 2012, and the extension is available for Windows but not for Mac.

Using Macro Features in Visual Studio Community 2013

US>The macro recording and playback functionality has been discontinued in Visual Studio 2012.
However, installing extensions in Visual Studio (Community) 2013 allows you to use macro features.

This is the current extension of the feature, but there is no information that it supports MacOS (there is macos in the Tags list).
Macros for Visual Studio

Or rather, there are very few extensions for Visual Studio for Mac and only eight.
Tag:macos search results

By the way, some people seem to want the macro function to be restored in the Windows version, but the feasibility seems to be poor.
Macros for Visual Studio VS2019

The answer to this article says that if you don't have it, you can make it yourself.
Visual Studio:short cut Key:Duplicate Line

Macrosolution (pre VS2017)
If you'd like to implement a more complete solution, perfaps to create a simple keyboard shortcut or you don't want to effect the clipboard, see this guide:

If you want to implement a more complete solution, create simpler keyboard shortcuts, or do not want to affect the clipboard, refer to the following guide:

The link provided in the following guide does not appear to exist now.
However, the contents of VisualBasic have been copied, so you may be able to make it yourself by referring to them.

Also, since the Windows version has a functionality, you can request that it be transplanted to the Mac version, and wait patiently if it is possible.