When operating a drone using googles (FPV), you need an observer. The observer must be in direct contact with the remote pilot, using phones or other communication devices is not allowed.

Remember to maintain required distances according to A1, A2 and A3.

Impl. Regulation (EU) 2019/947, Annex part A:
GM1 UAS.OPEN.060(4) Responsibilities of the remote pilot

The remote pilot may be assisted by a UA observer helping them to keep the UA away from obstacles. The UA observer must be situated alongside the remote pilot in order to provide warnings to the remote pilot by supporting them in maintaining the required separation between the UA and any obstacle, including other air traffic.

UA observers may also be used when the remote pilot conducts UAS operations in first-person view (FPV), which is a method used to control the UA with the aid of a visual system connected to the camera of the UA. In any case, including during FPV operations, the remote pilot is still responsible for the safety of the flight.

As the UA observer is situated alongside the remote pilot and they must not use aided vision (e.g. binoculars), their purpose is not to extend the range of the UA beyond the VLOS distance from the remote pilot. Exceptions are emergency situations, for instance, if the pilot must perform an emergency landing far from the pilot’s position, and binoculars can assist the pilot in safely performing such a landing.