It depends on what you want to copy:
- Indicators to the other charts of a split layout: open the Layout menu in the top bar and choose Copy indicators to other splits. It replaces the indicators already on those charts, and it cannot be undone.
- One indicator onto every chart: hold Shift when you click Add in the indicator library.
- Chart settings: in the chart's settings, use Apply to all charts. Symbols, intervals, indicators and drawings stay as they are.
- Indicator settings you reuse: in an indicator's settings dialog, open Templates and choose Save as template…, or Save as default so new copies start with your settings.
- A whole setup: publish the workspace as a Private layout (hover Layouts in the footer, then Publish current workspace), then open it in a new workspace whenever you need it. Workspaces, layouts, and widgets explains the apply modes.