To support CodeCommit on /changes, you will need to update the permissions to the vanta-auditor role.
Go to IAM Roles on your AWS Console and select the Vanta auditor role
Click the VantaAdditionalPermissions permission policy
Click Edit
Select Visual and select CodeCommit permissions
Allow the following permissions:
ListPullRequests
GetApprovalRuleTemplate
GetCommentsForPullRequest
GetPullRequest
GetPullRequestApprovalStates
Click Next
Save Changes