how can i turn off find my iphone from my apple account

See the information in: Turn off Find My on your devices - Apple Support including the following:

Before you sell, give away, or trade in a device, you should turn off Find My. When you turn off Find My on a device, the device is removed from your Devices list and Activation Lock is turned off.

If you no longer have the device, you can remove it from your account using Find My iPhone on iCloud.com.

Note: If you only want to stop sharing your location temporarily, you can hide your location. See Share your location in Find My in the Find My User Guide for Mac.