How to put a piece into an auction (artist)

Agree that one of your pieces is sold by bidding, and set the lowest price you will accept.

You will get an email for the piece, asking whether you are happy for it to be auctioned, with a link to read the terms. One link per piece, and you do not need an account to use it.
Read the terms on the page. They say what auctioning this piece means, and they are different from your consignment agreement, which promises the gallery will not sell above or below the listed price without asking you. This is that asking.
Enter your minimum bid. This is the lowest price you will accept, it is public, and bidding starts there. Nobody can bid below it. You set this number, not the gallery.
The hammer price may be well above your minimum — that is the point of an auction — and whatever it reaches is the sale price. The gallery keeps its usual commission on that, exactly as it would on a list price.
If nobody bids, the piece goes on sale at your minimum when the auction closes. You do not have to be asked again.
Tick the box and agree. The exact wording you read is kept, so a rate or a date that changes later cannot alter what you agreed to.
You can withdraw the piece any time before the first bid. After somebody has bid you cannot: they have committed to buying it at that price, and a piece that could be pulled afterwards would make every bid meaningless.
On a piece made by more than one artist, every artist has to agree separately. One of you cannot auction somebody else’s half.
While it runs, your own artist page shows it: “Your work at auction”, above your artworks, with your minimum, what it is at now, how many bids, when it closes, and whether you can still withdraw. Only you see that section — and the gallery, who can look at it with you over the phone.
You hear once, at the end: that it sold, for how much, and what your share of it comes to — or that it did not, and is on sale at your minimum with nothing needed from you. Nothing is sent while the bidding runs, so no news in the meantime is not a bad sign. On a shared piece every artist gets the same mail.
What you are never told is who bid, or what anybody was willing to go to — and they are never told what you would have accepted. That is in the terms you agree to, and it is what makes people bid at all.