Failed to connect to your instance

Hi,

One of the potential reasons you are getting the error "Failed to connect to your instance Error establishing SSH connection to your instance" could be that you have not allowed SSH traffic from your IP address. To resolve this issue, you should update the inbound rules of the security group associated with your instance to allow SSH traffic on port 22 from your IP address.

If you already confirmed that the security group inbound rules are correctly configured to allow SSH traffic (TCP port 22) from your IP address, and you are still receiving the "Failed to connect to your instance Error establishing SSH connection to your instance" message, there could be a few other potential reasons such as Instance State: Ensure that your EC2 instance is in the "running" state. If the instance is in the "pending" state, wait for it to transition to "running" before attempting to connect. Public IP or DNS: Double-check that you are using the correct public IP address or public DNS name of your instance when attempting to connect via SSH.

Check out these documents for further reference:

How do I troubleshoot issues connecting to my EC2 instance using EC2 Instance Connect?

Authorize inbound traffic for your Linux instances

Connect to your Linux instance from Linux or macOS using SSH

I hope it helps