Read this support article about what to do if a iPhone or iPad is lost or stolen -->
If your iPhone or iPad is lost or stolen - Apple Support
- The Find My service described in the article is the only recovery feature Apple offers. It must be set up before the device is lost.
- Note that if you remotely erase your device as instructed in this article, if you subsequently remove it from your account as in this article --> Check your Apple ID device list to find where you're signed in - Apple Support , then according to this article --> How to remove Activation Lock - Apple Support you remove activation lock from the device. Do not remove it from your account. If you do then a finder or thief will have an unlocked device that can be used by another person.
The people on this site are users like you. Apart from providing advice there is nothing we can actually do to help you with this.