SSH connection is being closed immediately after authentication, which suggests either:
- The repository does not exist at the given path
- The repository exists but the user (git) does not have access to it (maybe it's under a different username or organization)
- There's a server-side hook or configuration causing the closure.

Please confirm the exact repository path you used when creating via the web UI. For example:
- If you created it under your personal account: sinlee/openclaw-sync
- If under an organization: org-name/openclaw-sync
- Alternatively, you can provide the HTTP URL you see on the repository page, and I can derive the SSH path.

Also, you can test with:
ssh -T git@gitea.leexxx.com -p 61222
which should return a message like "Hi there, sinlee! You've successfully authenticated ..." if SSH is working.

Let me know the correct repository owner/name, and I'll adjust the remote and push.