Upgrade Amazon Polly

Anyone know the steps to upgrade Polly?

I tried the estimate then implementing. I inputted: "Number of requests (Neural Text-to-Speech) (50 per month), Number of characters per request including white spaces, but excluding SSML (1000)"

There's a "add service" then it goes to "configure service" and a bunch of options show up. Not sure what to select. If I then click "Summary" it goes back to "add service" I'm using it for a third party TTS program and that program just requires AWS key and secret. I've used up free tier.