$2000 deposit BEFORE auction?

As title reads, my partner and I (first home buyers) recently inspected a property in VIC we are interested in buying. I got a text this morning asking if we were interested in registering for the auction (bit confused by this also as in Vic you don’t have to register to bid at an auction, but they are telling us we do?). I replied yes and was sent a long text saying that we needed to transfer a $2000 holding deposit into their trust account and send a screenshot when we have done so. We have registered for a few auctions and never had to do this before. The text also said that if we are successful, the $2000 will go towards our deposit, or if we’re unsuccessful it will be transferred back to us within 24 hours.

Just wanting to get some opinions on if this is normal practice as we’re left feeling a little bit unsure by the whole process.

Thank you!!