Turn ON sandbox mode on AWS Cognito

Question

I use Cognito service for my users. I also use my SES with Cognito to send emails to them. I have two accounts on AWS - one for development and the second one for production. The development account uses my production domain when sending emails, and after many testing emails sending, the reputation of my domain decreased. Now I want to turn sandbox on on my development account for cognito and SES, but I cannot find where to do that, as the documention of AWS only shows how to go to production.