I agree with another comment that you should demand to be paid, rather than ask. But just telling someone to say "Fuck you. Pay me." doesn't actually answer the question.

If I were in that situation, and someone asked me to help with something that I didn't want to do for free, I'd tell them my rates.

"I need help setting up my WIFI. Can you help with that?"

"Sure. I charge $50/hr for tech work."

They're going to look shocked, upset, and probably angry. That's okay, because they were trying to use you and failed.

Then they're going to pull the, "I thought we were friends" or "You won't help a friend?" card. Tell them that you've got a lot going on in your life and are having to prioritize things. Tell them maintaining work-life balance has been hard, and you're trying to fix it because you've been overworking for quite a long time.

When all of that starts to make you feel guilty, ask yourself: "When was the last time they helped me with something they could do that I couldn't?" If the answer is "last week" or "a lot", maybe you should actually help them.

But when the answer is "I can't remember" or "never" (and it usually will be), you can just stop feeling guilty. They're just using you.

And it's okay to just say "No, sorry, I can't help with that." When people ask me to set up their wifi now, I just refuse. That's a huge pit of pain because they'll ask you back to help with every stupid thing they don't want to understand. I just flat refuse now for anyone other than very close friends and family. And I've got some family I'd tell "No", too.