It is called “Developer Command Prompt for VS 2017”, you can normally find it under Start > Visual Studio 2017 > Developer Command Prompt for VS 2017.
If you really don’t have it, then maybe some required components of VS 2017 are not installed. Please start “Visual Studio Installer”, click on “Modify” and make sure that the “Visual C++ core desktop features” component of the “Desktop development with C++” workload is installed (on the right side).
I hope this helps.