Github MCP tool doesnt work with Gemini CLI in codespaces

Followed the installation guide here.Method
1: Gemini Extension (Recommended)
The simplest way is to use GitHub's hosted MCP server via our gemini extension.

gemini extensions install https://github.com/github/github-mcp-server

Note

You will still need to have a personal access token with the appropriate scopes called GITHUB_MCP_PAT in your environment.

Despite all these setup steos above , while launching Gemini CLI , MCP server for github says cannot connect✕ Could not configure OAuth for 'github' - please authenticate manually with /mcp auth github

✕ Error during discovery for server 'github': Failed to handle automatic OAuth for server 'github'.

Then i tried to install manually /mcp auth github but still it fails with following error
✕ Failed to authenticate with MCP server 'github': Failed to fetch authorization server metadata for client registration (attempted
issuers: https://github.com, https://github.com/login)