Go to Items in the main navigation menu.
Press Custom Attributes in the upper right corner.
Press + New Product Attribute.
Under ATTRIBUTE CODE, enter “weight”. All letters should be lowercase.
Under ATTRIBUTE NAME, enter “Weight”
Under CUSTOM ATTRIBUTE TYPE, select Product attribute / number from the dropdown menu.
Under FRONTEND INPUT TYPE, select Text.
Under UI COLUMN SIZE IN POS, enter “3”
Press Save Changes.
Create a Weight Attribute
If you want to assign weights to your products, you'll need to create a weight attribute in the backend.