Hello @Christoffer2,
Only you are allowed to see your payment information.
The co-host feature is meant as an aid so someone else can help you communicate with and meet and greet your guests.
A co-host can message your guests and will see all your guest messages too. Co-hosts must have an Airbnb profile.
They aren't allowed to see your payment details.
I think that all you can do is to regularly send your accountant the file you get when you click on "Export to CSV" on your transaction history page. It can be per listing / per month etc.
From the co-host explanation on the website
The hosts you add to your listing can:
Accept, decline, cancel, or alter reservations
See and respond to guest messages
Edit pricing and availability
Edit the listing description (such as pricing, photos, etc.)
Interact with customer service on your behalf
Co-host can’t access your payout information or personal details. As the listing owner, you can remove them at any time.