How can you fix my battery?

Open Settings ➢ Battery ➢ Battery Health.

If the Maximum Capacity is 80% or less, then it’s time to replace the battery.

iPhone Battery Replacement:

Current Apple Prices:

• No charge for in-warranty or AppleCare+ plan.

Out of Warranty Prices:

• iPhone X or newer: $69 U.S. Dollars.
• Older models: $49 U.S. Dollars.

➢ Check AppleCare Coverage.

Click ▶︎ iPhone Battery Replacement.

Hello ~ We cannot as we are fellow forum users like yourself. Take a look here…

iPhone Battery Repair & Replacement - Apple Support

~Katana-San~