Instead of trying by hand, the optimizer calculates the combinations systematically and presents the best fifty as a table. One click takes a row over into the setup.
Depending on market and period, the run takes from a few minutes to almost an hour. It keeps running on the server even if you close the tab.
The row from the Top 50 is not a result but a suggestion. Anyone who tries a hundred thousand combinations inevitably finds some that look good in hindsight — even by pure chance. Why that is and what helps against it is explained in detail on the page about
Backtest & optimizer.
The one cross-check that is really worth it: take your setting and let it run on three or four other markets. If it roughly holds there, you have probably found something real. If it collapses everywhere except on that one coin, it has memorised that coin's past. In the mobile version this step is called basket evaluation.