Hi there, Axure has components as well, which work similarly to Figma’s. To turn your dynamic panel into a component, right-click it and then select Create Component from the context menu. Then, to edit the main component (and not just one particular instance of the component), navigate to the Components pane, and double click on the component to open it for editing.
I’d also like to mention that when you convert a widget (or selection of widgets) into a component, only that specific widget or selection is automatically a component instance. So in your case, since you already have your dynamic panel on two pages before converting one of them into a component, you’ll need to open the other page in your file, delete that dynamic panel, and then add the component version of the dynamic panel to the page. You can do this by selecting the component from the Components pane, and then dragging it onto the page, or you can right-click the component name and select Add to Pages… from the context menu.
I hope that helps!