In order to add a pension fund contribution to your invoice, you should first enable the function in settings.
In the top right corner of your main dashboard click on the name of your company and choose "Settings" from the drop-down menu.
On the left side of the next screen, you can see the settings for both your personal profile, and the company profile. From here, click on the option for "Invoicing".
On the right side, you will see several invoicing settings. Scroll down the page until you see the option "Enable Pension/INPS contribution". Click here to activate the function, and contribution will then become enabled once the button switches to blue.
Once it's activated, you will be able to choose your professional fund from the menu. The rate will change automatically according to the chosen fund, but you can also modify it yourself. If you are unsure which fund or rate to choose, please consult with your accountant.
Finally, to add a pension fund contribution to the invoice, open the invoice you need from the main dashboard. Then, in the bottom right corner, click on "Apply Pension/INPS contribution".
Now your invoice is complete, and ready to be sent to your client!