If the EA comes with indicators, should I attach them to the chart too?

If the EA comes with indicators, you generally don’t need to attach them to the chart separately. The EA will handle them internally.
However, if the EA requires additional indicators that aren’t included, you’ll need to place them in the “Experts” folder. To do this:

1. Go to File -> Open data folder in the MT5 terminal.
2. Navigate to the MQL5 -> Experts folder.
3. Copy and paste the indicator file into the Experts folder.