There are two types of offers:
Bid - when you make an offer to buy an NFT you are interested in.
Ask - when you put your NFT up for sale.
To put an NFT up for sale, just go to your NFT page and click on “List For Sale” (1), then enter the price and token in which you want to sell it (XRP by default) and sign the transaction in XUMM. After which your NFT will be listed and anyone can buy it at your price!
If you want to transfer NFT to another account, you can use Transfer (2). It will only be enough to confirm the transaction from another account. No one else can take your NFT.
If you are interested in some NFT, but the price is too high, you can make your offer - place a buy order. To do this, click “Make Offer” (1) and enter the price for which you are willing to buy this NFT. If the seller agrees, he will accept your offer and you will receive the NFT.
If you are satisfied with the price, just click “Buy Now” (2) and sign the transaction in XUMM. The NFT will appear in your wallet.