Hey Fixarn,
I see that you're having issues with your Microphone settings on your iPhone and I'd like the help.
To confirm, you're not seeing any apps under Settings > Privacy > Microphone. Is that correct? It's possible this is due to a Screen Time restriction that's been enabled on your device.
Tap Settings > Screen Time > Content & Privacy Restrictions > Microphone > Allow/Don't Allow Changes. From here you can enable changes to the microphone and also see apps that you can grant access to. For more information about Screen Time, check out this resource: Use Screen Time on your iPhone, iPad, or iPod touch
If you continue to have trouble, you can reach out to Apple Support directly. Here’s the link for it: Contact Apple for support and service
Have a great day!