The Hyundai warranty does not cover ignition coils, as faulty ones are typically considered general wear and tear. Both the Hyundai 5-year/60,000-mile basic warranty and the 10-year/100,000-mile powertrain warranty cover manufacturer defects only, so unless you can prove that it’s the fault of Hyundai, the company will deny the claim.
Most ignition coils last up to 120,000 miles, so this might not be the culprit. The only way to know for sure is to take your car to a mechanic and get an actual inspection. If you need an ignition coil, they typically cost about $200 apiece including labor.