Find my phone

If if is offline then you cannot track it.

Please first look at this - If your iPhone, iPad or iPod touch is lost or stolen – Apple Support

Tracking lost or stolen phones

The 'Find My' tracking is to help you discover if you left your phone in the office or the restaurant. Lost or Stolen phones are rarely ever seen again.

Risk mitigation

Get your provider to 

Cancel your SIM.

Send you a replacement SIM on same number.

You can then put the SIM in another phone to get the codes you will need.

Phishing warning

Unless you had a PIN set on the SIM the thief or finder now know your number so don’t respond to texts to sign into your account!

Resign to the fact your data is safe but you may never see the phone again 

Desertboyz13 wrote:

Last location of y phone how do I find my phone if it's offline

Did you have Find My Network enabled?

Use the Find My app to locate a missing device or item - Apple Support

See it on a map

Open the Find My app.

Choose the Devices or Items tab.

Select the device or item to see its location on the map. If you belong to a Family Sharing group, you can see the devices in your group.

Choose Directions to open its location in Maps.

If you turn on Find My network, you can see your device or item's location even if it's not connected to a Wi-Fi or cellular network. The Find My network is an encrypted anonymous network of hundreds of millions of Apple devices that can help you locate your device or item.