on this post i will show you how to create an inventor addIn solution/project via templates.

Visual Studio Templates

If you want to use the visual studio Templates you need to have the SDK installed.

The SDK : developertools.msi only supports Visualstudio 2017. If you want to use the template syou need to install a basic version of the VS2017 and then you can install the needed msi package.

The installer will copy some Templates in the folder

C:\Users\<User>\Documents\Visual Studio 2017\Templates\ProjectTemplates

you need to copy the templates to your VS Folder. In my case : C:\Users\<User>\Documents\Visual Studio 2019\Templates\ProjectTemplates. Now the templates will be avaiable in the template screen

With this template you should be able to create following project structure