If someone is poor and doesn't have the money, sure you can't enforce it.

If it's a corporation, it's pretty straightforward. If they refuse to pay, you get a writ from the court that authorizes seizure of assets.

Usually that means you go their bank and the value of the judgment will be garnished by their bank and given to you.

Occasionally and theatrically, a sheriff will take you to their headquarters to seize property like computers and printers that you can sell at auction until the value is satisfied.

It only becomes difficult if the corporation is bankrupt, which is similar to a poor person who doesn't have the money. Then it becomes a question of prioritization, e.g. do you get paid before or after lenders, and will there be any money left.