If you have good cash, just go to Dropcatch. They are now the best broker for this by far. If you find a domain expiring, they will probably have it in their list (90% of the times)
Personally I don't use dropcatch anymore, because regardless if noone is bidding for a domain, they won't autoassign it to you (in case you are the sole bidder), but catch it and put it on a bidding, which is obnoxious (essentially you are doing the dirty job for them).
But if you are beginning on this, this is the safest and simplest way to secure any domain (if you have the good cash to secure it, and outbid anyone else, obviously).
Nowadays PBN catchers just check the domains on biddings, and try to outbid. Most are too lazy to scrape and research by themselves.