Unable to submit request for production access to AWS SES service.

I have verified my domain and emails for AWS SES, and it is working fine in the sandbox environment. Now, I want to get access to the production environment on AWS SES. However, when I try to submit my request with enough details like mail type, site URL, use cases, and content emails, and click the submit button, I get the following error message every time: "Unknown error Request failed with unknown error, ensure that you have the necessary permissions and that all fields have correct values."

I have tried many times, but I still get the same error. I have a basic plan on AWS. I am stuck. What should I do next?**