Not able to connect ssh -i "test.pem" ubuntu@65.1.148.113

Based on your error message "Permission denied (publickey)", there are several potential issues that could be preventing your SSH connection to the Ubuntu EC2 instance:

1. Key file permissions: Your "test.pem" file may have incorrect permissions. Try running chmod 600 test.pem to set the proper permissions on your key file.

2. Incorrect username: Verify that "ubuntu" is the correct username for your instance. This is typically correct for Ubuntu instances, but double-check your AMI documentation.

3. Key pair mismatch: Ensure that the key pair you're using (test.pem) is the same one that was associated with the instance when it was launched.

4. Security group configuration: Check that your instance's security group allows inbound SSH traffic (TCP port 22) from your IP address.

5. Network configuration: Verify that your instance is in a public subnet with an internet gateway attached, allowing for outbound traffic.

6. SSH service status: The SSH service on the instance might not be running properly.

If you've verified all these settings and still can't connect, you could try:

• Using verbose mode for more detailed error information: ssh -v -i "test.pem" ubuntu@65.1.148.113
• Restarting your instance
• Using EC2 Instance Connect from the AWS Management Console as an alternative connection method
• Using AWS Systems Manager Session Manager if configured on your instance

If none of these solutions work, you might want to check the instance's system logs through the AWS Console for any clues about what might be preventing the SSH connection.
Sources
Failed to connect to your instance Error establishing SSH connection to your instance. Try again later. | AWS re:Post
Permission denied (publickey) - unexpected error | AWS re:Post
Instance not connect | AWS re:Post
EC2: Cannot connect anymore via Instance Connect or SSH command line | AWS re:Post