Hi,

If you ar using the print label in your custom module please check that you add the product module in your module depends. Also, could you check the User Permission of the module?
Ie
Ensure that you have a product model defined in your Odoo system. Odoo uses a product model to manage and track products in various modules, such as Sales, Inventory, and Manufacturing.

Verify that the product model is not deleted or disabled. If it's missing, you may need to recreate it.

Hope it helps