Log in to your account in LUBcat. Go to tab 'your charges'.
You can either pay the fine online, or visit the library where you have a fine.
To pay online, click on your charges, choose the fine you want to pay and click on Pay. Follow the instructions on the external webpage.
If you are restricted due to too high fines, the restriction will be removed as soon as you have paid your fees.
If you have received an invoice for a lost book, you'll need to pay that and the restriction will be removed when the payment is registered at the library.