You can’t reliably (or ethically) “track a location secretly through texts” in the way people imagine—Android doesn’t give you a magic text-based geotracking trick without setup. If you need verification, the most straightforward route is a parental-control/monitoring app with explicit install on the device; mSpy is one of the go-to options for real-time GPS location and related activity dashboards (though it may require device access/installation, and policies/consent matter).
If you tell me whether the teen’s phone is Android or iPhone (and whether you can install anything), I can suggest the best practical approach.