You may want to upload this extension to the Open VSX registry.

[felixniemeyer]

In open-source builds of code (= unbranded Visual Studio Code) this extension cannot be found.

That's because they don't not come with the microsoft extension marketplace configured and uses Open VSX registry per default.

You may want to upload this extension to the Open VSX registry https://open-vsx.org/ so that users of the open source build of code can find it easily.

Background about Visual Studio Code and OSS

Visual Studio Code is a distribution of the Code - OSS repository with Microsoft specific customizations, including additional source code and extensions, released under a traditional Microsoft product license.

source