Please increase my battery health

Battery health cannot be increased.

It is a function of use. The more the battery is used the less healthy it becomes.

If the health is under 80%, then you need to have the battery replaced. Link-> iPhone Battery Repair & Replacement - Apple Support

See if anything here helps

iPhone Battery and Performance   *

Battery and performance of iPhone 11 and later.    *

iPhone - About recalibration of battery health reporting in iOS 14.5.   *

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