I’m glad you were able to find the output! There’s actually instructions for viewing the output in the README for the extension:
https://github.com/elixir-lsp/vscode-elixir-ls/#check-elixirls-output
Were you looking somewhere else in the docs? Maybe we can add instructions there as well.
To make it more obvious I’ve created a PR to add a little GIF to the readme:
https://github.com/elixir-lsp/vscode-elixir-ls/pull/264
