This plant is almost certainly E. Oxypetalum by the look of the foliage.
A very popular night blooming 'Species' Epiphyllum that blooms mid summer.
It appears you are growing it as an indoor plant.
In early summer you could apply some bloom booster to encourage flowers.
It seems to be getting good light where you have it. If you are also using artificial light you may be interfering with the plant's natural cycle which may be why it hasn't bloomed.
Try growing it outside, under shade of course.
It looks healthy enough! Good luck with it.
E. Oxypetalum