How can I track my iPhone 11 Pro with IMEI number?

Don'ts

If the device is removed from an account after it is erased, Activation Lock will be turned off. This allows another person to turn on and use the device.

An example of my iPhone 5 is given in the GIF below. There is no "Undo" after you remove it from your account.

Find IMEI & Serial No. of the Lost Device

1. If an iPhone, iPad, or iPod touch is lost or stolen - Apple ...
2. Find the serial number or IMEI on an iPhone, iPad, or iPod ...

You may use a web browser to get the Serial Number and the IMEI Number. You cannot track using the IMEI number. but you may need it so keep it handy

Log in to https://appleid.apple.com with your Apple ID credentials. All your devices will be listed there. Click on any to get the details.

Do's, If you had enabled "Find My" before it was lost

• Mark As Lost.
• Erase your device. If your missing device is covered by AppleCare+ with Theft and Loss, you shouldn't erase your device. Instead, file a claim for your lost or stolen device.
• 

Beware of Phishing!

Be careful and be smart to --> Recognize and avoid phishing messages, phoney support calls ...

Note: Apple will never send you any info on Lost/Found iPhones. It (Phishing) may appear as the image given below.

Device Offline?

I see my device in Find My, but it's offline

If you see "Offline," "No location available," or "Location Services Off," your device might be offline for one of these reasons:

Don't see your device?

• You might not have Find My turned on.
• If you're using the Find My app, you can't see your device's location if more than 7 days have passed since its last location was sent to Apple.
• If you're using iCloud.com/find, you can't see your device's location if it's powered off, the battery has run out, or more than 24 hours has passed since its last location was sent to Apple.
• Learn how you can still protect your information.

Simple answer is you can’t The reason being is because you can get anybody’s IMEI number and then track them kind of like the situation going on right now with AirTags were people were putting AirTags in peoples vehicles without their permission and tracking their whereabouts the only way to track a device is if it’s an owned device that you are signed into in the Find My app.

You can’t. The only way to track it is using Find My.