If you are not able to see the Application name on the “Run” Button and instead you see below popup, its likely to below mentioned issues.

Issue 1
Visual Studio shows Run option only if a recognizable solution is opened. For example, if you have not opened the solution using the “.sln” file , VS will show option to attach any process to the same. In the above example, only standalone “csproj” file is opened in visual studio.

Solution:
Open the project using the “.sln” file and you will be able to see the Start Button/ a button displaying the project name as below:
You can look whether solution is opened on the solution explorer or on the top bar as highlighted below:

Issue 2
It is possible that the dotnet environment variable is not set. Please find below steps to update the Environment Variable
Solution:
- Press Windows + R to open Run Box
- Enter the command : rundll32.exe sysdm.cpl,EditEnvironmentVariables
- Edit the PATH variable in the System Variables, and add the location of the dotnet.exe (Ex. C:\Program Files\dotnet)
Please let us know about your suggestions in the comment box.