Can a switch from a timing belt to a chain belt in my 2007 hyundai accent hatchback?

Timing chains are located where they are lubricated in motor oil. Timing belts are not. So putting a chain in the belt's location will not work. Not a bad idea, but no.

Thank you. So, basically there is not a single chain timing engine does fit my Hyundai Accent 2007 Hatchback?

That's correct. Your car has a belt. You can not use a chain as a replacement. They don't make one. It would not work. Get your belt replaced at 100K miles or risk engine damage when it breaks.