There is fluid leaking from the transmission to the engine gasket.
I assume the leak you are seeing is coming from the transmission bell housing where the engine meets the transmission. If fluid is leaking from here it is most likely the front transmission pump seal where the torque convertor goes into the transmission. The transmission would have to be removed and the seal and transmission front pump inspected and repaired as needed. Sometimes the seal just needs replaced and sometimes more major repairs are needed to the transmission due to a front pump problem. Only a transmission removal and inspection by a qualified mechanic can diagnose the problem correctly. I recommend you have a mechanic, like one from YourMechanic, inspect your vehicle’s leaking issue.