i am trying to setup a whatsapp api for my business namazeven.com.

whenever, i am on API Setup, i get this warning: Send and receive messages Step 1: Select phone numbers From Send free messages with the provided test phone number. You can use your own phone number which is subject to limits and pricing. Learn more. From Test number: +1 555 068 0293 ​ Messaging may be unavailable. Review issue

and send message button and Run in Postman buttons are inactive.

I guess it is because i had another business asset, and previously i tried to setup Whatsapp API for that. Therefore i deleted almost everything about them. However i can't delete "Test WhatsApp Business Account" with account id 366472366551780. it keeps giving this error that i have attached a phone number to it. and I can't delete that phone number no matter what i tried. Can you please fix this issue asap, so that I can create a new whatsapp api for my application. Thanks