Growing a form for a different number of lines


I'm working on app to add invoices to my database. Every invoice has a different number of line items. Whats the best way to create a form in Retool that let's me add as few or as many line items as i'd like? I've seen forms where I can "add another line" for each line item, and that is my preference if it's available in retool. I searched but I couldn't find a relative answer.