Product review (4 stars): Part fixed gas dryer but...
Intuitively one would think the gas valve in a gas dryer would either work or not. But apparently it's relatively common for these coils to somehow become "weak" and they only work some of the time. The result is the dryer gets warm but not as hot as it should and drying times are much longer.

These non-OEM replacement coils fit and worked perfectly. They fixed my dryer. I did, however, knock one star off as the vendor (Appliance Parts Stop aka Pricelesssupply) claimed "same day shipping before 3pm" but took an extra day to ship the order.

It's easy to confirm if these coils are likely the problem with your dryer. If the ignitor ever glows but there is no flame it's likely there's a problem with the gas delivery. And these coils are the most likely problem that will keep the gas from flowing. If replacing them doesn't fix the problem, and the ignitor is glowing, you likely have a gas supply problem or need to replace the entire gas valve.