Greetings RayanAbdulaziz,
Thanks for visiting the Apple Support Communities! I understand you're unable to locate the setting to allow access to the microphone for app on your iPhone.
I suggest checking the Screen Time restrictions on your device, as the microphone may be restricted. Check out the "Allow changes to privacy settings" section of the following support article: Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support
If the issue isn't related to Screen Time restrictions, then ensure you're viewing the proper setting to allow access to the microphone: Change app access to information on iPhone - Apple Support
If the issue persists, test the behavior after reinstalling the app: How to delete apps on your iPhone, iPad, and iPod touch - Apple Support
Kind regards.