Permission Deny Occurs When Attempting to Back Up Files from EC2 to S3

Hello,

Can you try the below

• Assign a S3 bucket policy as below example policy that allows the ec2 instance to write.
• If you already have a role assigned to ec2 then you can use the same in the policy, else create new assume role for ec2 and assign that role to ec2 and use that role arn in below policy.
• the second statement in the policy is basically a best practice to allow only https (not related to the error you are facing)

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "AWS": "arn:aws:iam::123456789:role/role_that_is_assigned_to_ec2"
            },
            "Action": [
                "s3:ListBucket",
                "s3:GetObject",
                "s3:PutObject",
                "s3:PutObjectAcl"
            ],
            "Resource": [
                "arn:aws:s3:::bucket-name",
                "arn:aws:s3:::bucket-name/*"
            ]
        },
        {
            "Sid": "RestrictToTLSRequestsOnly",
            "Effect": "Deny",
            "Principal": "*",
            "Action": "s3:*",
            "Resource": [
                "arn:aws:s3:::bucket-name",
                "arn:aws:s3:::bucket-name/*"
            ],
            "Condition": {
                "Bool": {
                    "aws:SecureTransport": "false"
                }
            }
        }
    ]
}