Dryer is not heating

We are trying to repair our dryer. The first thing that happen was the Auto Drying was not working as I described in a previous post. It was running non stop. After awhile it stop heating. My husband replaced the Flame sensor, but it still is not heating. You can see that it is trying to start, but is like is not getting gas. we are considering to change now the Coil Kit.
We are wondering if is anything else that need to be change before we place our order for parts.

oven cycle light is on constantly. Oven temperature does not set or stay at set temperature