How do i get vs_buildtools.exe?
You already have vs_buildtools.exe.
I installed Visual Studio Build Tools 2017 using the link (at the bottom of the “Other Tools and Framework” section), setting both workloads
You will notice that the name of the installed file is vs_buildtools__339506979.1501125082.exe , which includes version information in the name. You can rename it to vs_buildtools.exe, here is what you need.
Update for vs_buildtools.exe:

After using the command:
vs_buildtools.exe --add Microsoft.VisualStudio.Workload.WebBuildTools
WebBuildTools will be installed at:
C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\MSBuild\Microsoft\VisualStudio\v15.0\WebApplications
Also, keep in mind that comment in response:
If you have already downloaded "Build Tools for Visual Studio 2017" (visualstudio.com/thank-you-downloading-visual-studio / ...), then you can run this installer, click "Edit" and check "Create web development "check the" workload module "box. Then click the Modify button and allow the installation to complete.
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