You'll notice that Paragon comes with some default attributes. One of which is the 'unit of measure' attribute.
First, navigate to the attributes screen by hitting the attributes setup card from the settings screen.
Next, search for the 'unit of measure' attribute, or scroll down until you see it. Hit the edit button on the right side.
Here, you'll see a list of unit of measures. You'll also notice the boxes on the left side of the measurement, meaning you can activate, or deactivate the measurement.
To activate a unit of measurement, check the box. This unit will now be visible when you add a product BoM to your items.
To add a new unit of measure, hit the blue add new button. A blank row will show up, and you can enter the name of the measurement.
Activate the unit of measurement, by checking off the box on the left hand side. This UoM will now be visible when you add a BoM to your product.
Once you're done, hit the next button until you have the option of hitting save changes. Save your changes, and you're done!