If someone wants to live, could it make them live longer?

There have been thousands of examples of this. People holding on for just one more event before finally letting go. Like a parent dying just a week after their daughter gets married. David Bowie dying just days after the release of his new album on his birthday. Things like that.

Human will is stronger than anything else out there. The will to live is what makes us live in the first place.

Yes, it's quite simple because someone that doesn't want to live is probably depressed which makes the person avoid taking care of themselves and doing any activity, and as a result their health deteriorates.
I'm sure you can find plenty of researches with Google.