The same is with everything else. A company produces cars and then they put numbers in accounting books to express quantity of cars.
No, it's not and that's where you're wrong. When I have a signed contract that says I own 10 cars, those represent something that exists. When my bank account says that I own $100 those
cash supposedly exist. The hundred dollar bill ALONE does not represent something that exists. It's not debt UNTIL it's loaned. That's same for everything; they don't create debt until they're loaned.
The central bank issues banknotes that don't represent ANYTHING at first.