Carrier rates and free shipping limit
When you are configuring shipping rates and pickup points to Packrooster Shipping, you can set a free shipping limit to each delivery rate. This can be done in Packrooster —> Settings —> Shipping methods —> Click on the shipping method —> Price —> Free shipping limit.

There is an important thing to take into account when activating a free shipping limit in a shipping rate in Packrooster. All third party carrier apps like Packrooster Shipping get the data of the order, items and customer from Shopify's carrier service request. The order value always arrives in Shop currency, not customer currency.
This means you can't configure the free shipping limit in customer currency, as Packrooster always gets the order value in shop currency, even if the customer uses different currency configured in Shopify Markets.