I've lost my iPhone and can't use the Find my app

You need the Apple ID to use find my

If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support

if you have other devices to look, see: If you've forgotten your Apple ID email address or phone number – Apple Support

See if you've already signed in with your Apple ID

Check if you've signed in on your device. Or check if you've signed in to Apple apps or services.

Other ways to find your Apple ID

• Check if you’ve signed in to the App Store, FaceTime or Messages on your iPhone, iPad or Mac, or check if you’ve signed in to iTunes for Windows on a PC. 
• Go to iCloud.com or appleid.apple.com and see if your Apple ID prefills on the sign-in screen. 
• If you’re part of a Family Sharing group, you can ask a family member to check their Family Sharing settings for your Apple ID

Hello Lostphonelol!

I am very sorry to hear about your unfortunate situation.

Here’s how to Use the Find My app to locate a missing device or item - Apple Support.

Also see: If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support.

I hope this is helpful. Good Luck!