You can find this at Point programs tab > Redeem points > Click Add more button > Choose Free shipping option:
In the setup window, you can see options to:
Once you are done with the setup, click Save.
If the shipping amount of the order exceeds the maximum amount, customers cannot apply Free Shipping code. This setting is optional.
For example: In the screenshot below, the order has a 40$ shipping amount (exceeding the 30 EUR maximum), therefore it could not benefit from the code:
They will need to go to the widget/loyalty page > Redeem point > click the Redeem button on the right to the option.
To view more info, click on the “i” logo next to the reward title.