Hi @jing tung wong ,
Good to help you!
1. Create one server action and call your aggregate data which you want to download a Excel.
Here in my example I'm taking Sample Database Product Entity.

2. Install this plugin in your environment. Add dependencies as well of client action named as Save File

3.. In Screen Create one button name it as Download Excel call the server action that created on Top.
Inside Button's client action call Above created server action and save file client action from file plugin

To the client pass the needed Binary file and file name.
I hope this helps.
- Palle Vijay Bhaskar Reddy