You have paid a rental deposit at the beginning of your rental contract. Rental damage is deducted from that deposit. Other costs may also be deducted from the rental deposit, such as rent arrears, energy costs etc.
Is your rental deposit on an escrow account? If so, contact the bank where the deposit was deposited for a release form.
Did you pay the rental deposit directly to the landlord? Then the landlord must refund it to you.
There are three options:
There is no rental damage: the landlord must return the full rental deposit, minus any outstanding charges (for example water or energy settlements).
There is an agreement on the rental damage: fill out the release form accoring to the division you agreed on with the landlord.
There is no agreement on the rental damage: can you and the landlord not agree on the rental damage nor the release of the rental deposit? Then you can file a lawsuit with the justice of peace. Make sure you keep all documents as evidence, including the inventory.