Procedure
1. Access the product edit page for which you want to apply the restriction.
2. Click on the plugin tab named Calcolatore metri quadri.
3. Scroll to the configuration section titled Larghezza.
4. Locate the Valore Predefinito field and make sure you have set the value you want the customer to use.
5. In the same section, locate and check (tick) the checkbox labeled Valore non modificabile.
6. Click the save button (usually Salva or Aggiorna) to apply the changes.
Once saved, the Width field will be visible to the customer but cannot be modified and will automatically use the set Valore Predefinito.
