git submodule on github codespaces

I have problem with submodule on github codespace.

When i use command

git submodule update --init

terminal show me

Warning: Permanently added 'github.com,xxxxx' (ECDSA) to the list of known hosts.
    git@github.com: Permission denied (publickey).
    fatal: Could not read from remote repository.
    
    Please make sure you have the correct access rights
    and the repository exists.