Since the part is designed in a liquid environment and built layer by
layer. Therefore, support structures are needed to increase the rigidity
of the part and prevent cases of overhanging parts from sinking or floating
freely.
When exporting the STL file, make sure that the STL file is refined enough for your usage. Also, remember to give the units of the STL file to person doing the SLA process because units are not stored in STL files.