Bring a group over

From Splitwise or Tricount. Balances come out the same.

A Tricount link

In the tricount, tap Share and copy the link. Everything comes in, straight from Tricount.

Or an export

Where do I find it?

Splitwise: open the group on splitwise.com, then the settings gear → Export as spreadsheet. You get a CSV.

Tricount: in the tricount, open the menu → Export and pick CSV (Excel works if you save it as CSV).