By clicking on your profile at the top right of your back office, you can access the billing page.
For your information, this is all done through Stripe.
Then, to access your invoices, click on "Access my invoices and payment methods".
You will then have access to all your invoices.
You can also change your payment methods and set up SEPA direct debits.
The Customer Success team remains at your disposal if needed: contact them here.