The step counter does work when you are offline.
However, you have to be online when you convert your steps into Wards. If you don't have an internet connection, it won't be possible to convert your steps.
When you do have an internet connection, then your steps will be recorded and accounted for and you'll also be able to convert them.
Please note: steps counted while offline can only be converted for Wards if they were taken less than 3 days prior.
Happy walking 👣