how to turn off sound when dialing on iPhone 7

How do I permanently turn off the sound of the keypad only without constantly using the switch on every call? I still need the system sounds and sound alerts on. If I leave the silent switch off I do not get my alerts or cannot hear my calls - this switch make my phone unusable. Is there any other way to just disable the keypad sound like keyboard click on/off option? Thank you

Flip the ring/silent switch on the left side of the phone. This will turn off all the notifcation- and system sounds.