If you see the following error whilst deploying:
We couldn't access your repository. Please ensure the authentication details are correct.
Firstly, if using SSH to connect, you'll need to make sure your SSH key is added to your repository host, or for HTTP, check the username and password credentials are correct. If you need to update your repository details, you can follow this guide.
This could also be caused by a firewall issue on your server. Firstly check the connection is for the correct port, SSH uses port 22 by default, and HTTP uses port 80. If you're connecting to a self-hosted repository (GitLab etc.) then this may use a different port.
You'll also need to whitelist our IP address ranges to enable DeployHQ to connect.