How can I cancel my iphone insurance

If you're talking about an Apple Care Plus Protection Plan, see this article:--> Cancel or change the payment method for your AppleCare plan - Apple Support

If you have a different insurance, contact your insurance company and ask them.

Regards

Giulio

If you bought Apple Care plus and you paid upfront for 2 years you can call Apple Support to cancel it and have a refund for unused months, if you pay monthly you can either call The Apple Support or doing it yourself in your Apple Care+ account