Probably scam. Check back in few hours, you'll see that the account will be banned. Carousell is pretty fast detecting bot accounts. Oldest trick in the book will be they try to make you message them outside carousell. Latest I heard they ask for your email because they can't pay via carousell pay.

First step is always to get your personal number/email so that they can slowly fish you in to make you believe that they're a legit buyer, later will ask you for payment to release bank payment. This may sound very stupid trick, but it worked since the beginning of online scams and has been proven the best low effort scam out there.