2017 Hyundai Sonata Limited. The three buttons on the interior Trunk, Gas, traction stopped working.

Bulb is number one reason. Fuse is number 2 reason. You are not alone :>)

https://www.google.com/search?q=2017+hyundai+sonata+sport+replace+trunk+light+bulb

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https://www.youtube.com/watch?v=i2TVuBp-n0Y
Must be a common problem. Here is a video of where the emergency release is.

This fuse box diagram show a power outlet fuse in the inside fuse box. It also shows two fuses and a relay in the engine compartment fuse box.
https://www.autogenius.info/hyundai-sonata-hybrid-2017-fuse-box-diagram/
The relay says for 3 power outlets
One of the fuses says for cigarette lighter
If all the fuses are good the outlet which does not work may have shorted and blew the fuse. Check outlet to see if it has power to it.

The cable came loose in the truck. It is probably under warranty, the dealer will replace whole cable. If not, then look and you will see a bracket that the cable has come off of. Just push back in.

It's highly probable that the nipple has come off the cable inside,remove the panel and inspect.

Pull out the warranty and read the terms. We have no idea what terms are in YOUR warranty

On the internet it said the Hyundai Dealer can make you a cheap key for only the trunk, which is cheaper than the regular key if you provide VIN information and proof that you own the vehicle.

If you have another key, or already ordered and received a replacement key, you might still have problem opening trunk, and another person said "Easy way is to press the unlock button on the driver's door. Then the trunk release will work."

Not if they are gas charged struts, but could be replaced. Take both struts off at one end and see if that was the problem with difficulty raising the trunk lid.

It is either accessed through the trunk from underneath or the cover can be removed from the back of the light assembly and they can be replaced that way