You don't HAVE to... But should you? Yes...
Every ink, every material, every shop is different... Theres different temps, different amounts of solvent in the ink, etc. So there is no magic number.
Ink is comprised of pigment, and "solvent", like rubbing alcohol. It takes more than minutes for the solvent to evaporate... It takes more than hours for all the solvent to evaporate. If you laminate it right away, All that solvent gets trapped, and wont evaporate.
Does that mean it's going to cause you issues? That all depends. We've laminated something 10 minutes after with no issues. We've also laminated something hours after, and had every single sign fail. Theres too many variables to tell you what you should do, and how long you should wait. We try to let it offgas overnight... But of course rush jobs happen, and we end up laminating it within an hour of the print. 90% of the time it's ok, but why risk it if you don't have to?
If you have time, let it offgas... If you don't, then don't. Just be prepared for the chance of a redo. It's not as big of a deal as some people make it out to be, but why cut corners unless you 100% have to? Design your workflow around offgassing, and you should be able to offgas 99% of the time.
For faster offgassing... if you can weld, you can easily make a "prop" to help. All you need to do is blow a fan under, or ontop of the roll. You could theoretically even loosen the vinyl so it's not tight on the roll, have the roll standing up with the plastic core holder, and hang a fan overtop of it.
But even then... Whats the magic number? an hour, 2, 12? It's best to let it sit at least overnight.