This is a fitting can be used for both types of drain lines. This fitting comes with 2 washers so even if your surface is slightly curved, this fitting will squish down and make a seal.
Whether you are creating their own ebb and flow system or simply replacing missing or worn components, the Sunleaves 1/2” Fill and Drain Kit has them covered and includes a 1/2” Fill Fitting, 3/4” Drain Fitting and two 1 1/4” Drain Risers and Drain Screens.