If the call recording option not showing, please follow the below steps:
1. In Google Dialer Call record option is available on the next screen. Please click More icon to see the Call record option as per the below image.
2. Please go to Google Play Store to update app, and try again.
3. Please check the update and update the device.
4. If still issue not resolved, please reset the device and check.
If the above methods do not solve your issue, it is recommended that you bring your device along with the purchase certificate to the nearest authorized realme service center for support.