D-link extender setup could be done by three ways:
Using D-link setup wizard from web browser(via dlinkap.local or dlinkrouter.local)
Using Web protected Setup (WPS)
Using QRS mobile app
Prior to D-link extender setup, ensure following few points:
Make sure to fully extend the antennas on the D-link range extender for optimal wireless coverage.
D-link wireless range extender should be positioned within the wireless signal range of the Access point or the home wireless router.
Optimize the D-link wifi extender location using smart signal LED indicators after D-link extender setup for better wifi signal.
D-link extender setup using the web browser (dlinkap.local or dlinkrouter.local login) is not supported on smart phones, and you would require QRS mobile app to configure your d-link extender using mobile phones.