Unity Terrain river?

okay i want to make a really long river that winds and i cant seem to find out how i do that exactly i’ve tried the six times nothing asset but he is on windows and i am on a mac so i am confused on what i do any suggestions?

could you clarify the six times nothing asset and whoever he is? Thanks.
for a River you could make your terrain with a riverbed, and then add a huge mesh spanning the whole terrain and give it the water shader (or use the prefab). then make it the height that you want and INSTANT RIVER!!