You can find the partnerID yourself by logging into your FINN business account, choosing "innstillinger" in the top right, then "bedriftsinnstillinger" from the dropdown menu and then on the page you get, you choose Partner ID, and you will see your partnerID.
Choose your company in For Bedrifter. If you do not have one, you need to get your email connected to your company either by asking our sales department or someone in your company who already has access.