How can I find my iPhone when location is off?

Hi

If Find My iPhone is enabled on your iPhone, turning on Lost Mode will also turn on Location Services.

To turn on Lost Mode and locate your iPhone using Find My iPhone, follow the instructions here:

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

The article also recommends steps to take if Find My iPhone is not enabled on your iPhone.

Take a look at this article, it may help you If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support