My iPhone 14 battery health drop 97% in just 3 month

Hello Sultan. It's completely normal for your battery health percentage to drop 1-2 percent per month. Battery health Percentage is based on usage and cycle charges. The more you use your phone and have to fully charge it, the more the battery health will drop.

Keep in mind batteries naturally degrade over time.

Please see the following articles on how to maximize your battery performance:

iPhone Battery and Performance - Apple Support

Batteries - Maximizing Performance - Apple

It is normal to expect a 1 to 2% drop per month. When the battery health drops to 80%, get a new battery.