Cannot save Amazon SP API Settings

[akkrause]

I receive this message when I save Amazon SP API Settings.

    Error: invalid_aws_credentials
    Error Description: An error occurred (InvalidClientTokenId) when calling the AssumeRole operation: The security token included in the request is invalid.

Amazon no longer provides AWS credentials or AWS IAM for Private Developer because they are not needed. See Amazon announcement:

    https://developer-docs.amazon.com/sp-api/changelog/sp-api-will-no-longer-require-aws-iam-or-aws-signature-version-4

Refresh Token, Client ID and Client Secret were assigned by Amazon through Amazon Seller Central->Developer Central.
I filled AWS IAM, AWS Access Key and AWS Secret Key with random values because they are required fields for the form.

Ecommerce Integrations: v1.19.6 (main)

ERPNext: v14.65.3 (version-14)

Frappe Framework: v14.67.1 (version-14)