Build an apple app

I need to build a simple apple app I want to build an app to answer questions simple it’s a chat Gpt3 app I will provide api I want an app to open have a microphone to speak or text and ask chat Gpt3 questions and thru api answers will be typed and spoken back to user similar to genie or any chat Gpt3 app just want to simplify it and sell it on App Store will get into details later