well that's not what their website says !
https://www.airbaltic.com/en/checked-baggage
On airBaltic flights, the maximum weight of one piece of checked baggage is 20 kg,
If any piece of checked baggage exceeds the 20 kg per bag allowance, passengers will be charged a 50 EUR heavy baggage fee. This charge is applied per bag not per kg. The maximum weight of one piece of checked baggage is 32 kg.
(their bolding)