If you ever wish to copy a project, together with its tasks, into another app such as Microsoft Excel, you can do that using the Copy action which can be found in the bulk editing menu.
To copy an item, just ctrl/shift-click it which will open the bulk editing menu on the top where you'll see the "Copy" button:
When you click on the "Copy" button, Marvin will save the selected items to your clipboard in the following format:
π© Project
Task 4
Task 3
Task 2
Task 1
If you wish to paste these tasks and projects into a Markdown file, you'll probably want to save them as a task list:
[ ] π© Project
[ ] Task 4
[ ] Task 3
[ ] Task 2
[ ] Task 1
To do that, go to β° β Settings β Interactions and enable the "Copy tasks as Markdown" setting: