Privately access code commit repo

Hello.

Try adding the following policy to the IAM user's policy.
If you add this, you will not be able to access CodeCommit unless you go through the VPC endpoint.

{
  "Version": "2012-10-17",
  "Statement": [
      {
          "Effect": "Allow",
          "Action": [
              "codecommit:*"
          ],
          "Resource": [
              "*"
          ],
          "Condition": {
              "StringEquals": {
                  "aws:sourceVpce": [
                      "VPC EndPoint ID"
                  ]
              }
          }
      }
  ]
}