After confirming your participation on the desired auction, a screen will display all submitted comments, rules and negotiation status
On Negotiation Summary panel, you can see your ranking position (if the necessary option was set in this auction), a stopwatch (which displays the remain time to submit your bids) and your previous bids submitted for the specified item.
Report your bid on the equivalent space of the item you desire. then click on Offer.
If there is more than one item, after reporting all desired prices, click on Confirm to submit your answer.
In order to automatically fill in the bid price, seeing the initial value set for the auction and the decrements or increments, click on OFFER ALL to fill out all items or in the HAMMER icon for bids per item then click on CONFIRM ALL to submit your response.