You can manually download the .vsix file, from either Savannah’s
download area,
Open VSX Registry, or the
proprietary Visual Studio Marketplace.
Before you install a .vsix file downloaded from a third party,
you should check whether the file matches a trusted signature:
wget -O- 'https://sv.nongnu.org/people/viewgpg.php?user_id=214244' \
| gpg --import
wget -O- https://dl.sv.nongnu.org/releases/vscode-texinfo/texinfo-0.3.0.vsix.sig.asc \
| gpg --verify - texinfo-0.3.0.vsix
Finally, install the .vsix file to Visual Studio Code via command
palette: Extensions: Install from VSIX....