Currently, you are not able to use an Amazon partnered carrier to send a shipment that contains Hazmat items. Due to this, you won't be able to send box weight and dimensions for the shipment from InventoryLab.
If you attempt to enter box weight and dimensions for a Hazmat shipment, you will be prompted to enter them in Seller Central.
Click Skip this Step and wait a few moments for a green Success message in Stratify.
At this point, you can move on to Seller Central to enter the weight and dimensions for your boxes.
You will need to purchase shipping and tracking from a carrier outside of Amazon and enter the tracking information after you mark the boxes as shipped.