Can't find a requirement to use but,
JAR–OPS 1.640 Aeroplane operating lights
An operator shall not operate an aeroplane unless it is equipped with:
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(b) For flight by night, in addition to equipment specified in paragraph (a) above:
(1) Navigation/position lights; and
(2) Two landing lights or a single light having two separately energised filaments; and
(3) Lights to conform with the International regulations for preventing collisions at sea if the aeroplane is a Seaplane or an Amphibian.