The Inputs tab is where you set the commercial terms of a proposal — how the customer pays and how the price is adjusted. It's the first tab when you open a proposal, and the running price per watt and total price update live as you change these fields.

The Inputs tab — Payment and Adjustments, with the live Total Price on the right.
Pick the Payment Option (e.g. Cash or a financing product) — the filter icon narrows the list to the options that apply. When the deal includes HVAC, an HVAC Payment Option appears here too.
Fine-tune the price: apply a Discount (dollar or percent) with a Discount Name, choose a Promotion (e.g. a seasonal offer), set the FTC Rate used for the federal tax credit. The Total Price panel on the right shows the resulting price per watt and total.
Record an Up-Front Rebate and up to three Back-End Rebates, checking the box next to each one that applies.
Add extra line items — Adder 1–5 — each with a Quantity and Amount, for anything priced on top of the base system.

Rebates and Adders at the bottom of the Inputs tab.
Open any proposal from a customer's Proposal List; Inputs is the first tab. See Proposal Builder > Overview for a tour of the other tabs.