Note that this feature doesn't work in open source builds of VSCode, it's an MS only thing.
By packaging it as an extension that isn't licensed like the rest of VSCode.
Also on a related note, if you're using an open source build of VSCode (such as VSCodium) then you cannot use marketplace.visualstudio.com/
https://github.com/VSCodium/vscodium#extensions-and-the-mark...
A FOSS build is available at https://vscodium.com/
They want Theia to be a tool to build your own editor and it can be built as a hosted solution (like code-server) or a standalone editor
Edit: I see that the article also mentions Theia but this point about Theia vs VSCode is not mentioned.
https://github.com/VSCodium/vscodium/blob/master/DOCS.md#pro...