Hello Amawah,
Thanks for connecting with us here in Apple Support Communities. It appears that you're having some issues with listening to audio messages while using WhatsApp. Have you tried restarting your device since noticing this behavior? See: Restart your iPhone - Apple Support
"How to restart your iPhone X, 11, 12, or 13
- Press and hold either volume button and the side button until the power-off slider appears.
2. Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
3. To turn your device back on, press and hold the side button (on the right side of your iPhone) until you see the Apple logo."
If you still have trouble after the restart, please connect with WhatsApp Support here: https://www.whatsapp.com/contact/
Have a great day.