Backyard Sauna Is It Possible To Construct A Sauna Bath Or To Purchase One?

Is it possible to construct a sauna bath or to purchase one? - backyard sauna

5k run every day and the days, I can not walk, I do other exercises, as they include a gym treadmill, I heard that the sauna is good for you to say, especially when it is taken after training. Can you bath them in my garden? How? or can I buy rewady done. I live in a fairly remote location in northern India.