Looking at those dark leaves, it is almost certainly Cestrum elegans
'Scarlet Cluster'. A very nice variety and moderately hardy out of
doors in milder regions of the south. It can develop into a pretty
large shrub in time - well over 3m. high and across. As a greenhouse/
conservatory shrub, it lends itself well to container culture and can
be hard-pruned in autumn or spring if it gets out of hand. It also
makes an excellent 'patio plant' in regions where it cannot be kept
outside permanently. A sunny spot and regular feeding will ensure
almost continuous flowering.