lubuntu – How can I make it so that suspending my laptop locks the screen instead?

My laptop goes into a black screen when it wakes up from suspend. I’ve already made a post about this, but it didn’t get much attention. From the looks of it, updating my UEFI-based BIOS may solve this, but I’d need a professional to do that. The other option if that doesn’t do it is to get the laptop repaired.

Until then, I’d like to set up something so that suspending locks the screen instead. I think that there’s a file that lists actions and associated outcomes about suspending, locking the screen, closing the lid, etc. For example, if I shut down using the shutdown utility, the laptop shuts down. But, if I changed the corresponding thing for that in the file, I suppose I could make it so that using the utility suspends instead. I want to do something like that but for suspending.

Does anybody know what file I’m talking about? Otherwise, what else can I do to get what I want?

I’m on Lubuntu 21.04 by the way.