how to vibrate Iphone 14 Pro Max when call is answered from the other side?

The only notification you will receive when the phone is answered is the person on the other end saying "Hello".

What does “answered from the other side” mean exactly?

• An iPhone can only answer calls from one side - the side with the Home Screen.
• An iPhone cannot be made to vibrate once a call is answered. It may vibrate before the phone is answered.

Ah, likely IdrisSeabright correctly concluded what “answered from the other side” meant. That did not occur to me.

If that’s what it means, you do actually receive another notification. The clock shown here as “00:02” here activates once the phone is answered.

Ah, that's a good point!