Fixing a dryer is generally DIY, even with propane; the type of fuel
should make no difference. For a no-heat problem on a gas dryer, these
are the common points to look at:

1. Ignitor open.
2. Coil open.
3. Thermostat or thermal fuse open.

Here is the diagnostic trail, simplified: When there is a call for heat
(you turn on the dryer), you should hear the clang of coils setting up
the the valve for fuel. There are actually 3 coil circuits within the
2 coil units. If you don't hear that clang, this would point to a
thermostat/thermal fuse problem. If you do hear the clang, then this
would point to an ignitor problem. Lastly, If the ignitor glows, then
this would point to a coil problem.

Maytag dryers are generally very easy to repair because an internal
front bulkhead holds the drum in place, allowing you to take of the
front, leaving the wires connected, and diagnosing the problem with
power to the machine. This is a bit more "dangerous", but will give
you accurate results.

Take off the front, and move out of the way, but leave wires connected.
Put the dryer into a heat cycle, press start, and see if the ignitor
glows. If not, do a voltage drop test at its connector. If you get
120 at the connector, then replace the ignitor. Next, while the drum
is turning, you can do voltage drop tests across each thermal fuse and
thermostat, which are located on the blower housing and on the burner
housing. If you find a voltage drop of 120, then this is the component
to replace.

When I say voltage drop, I mean testing for potential by placing your
meter leads on the 2 wires that feed a component. If the circuit is
closes, you will get no drop, but if the circuit is open (or in our
case, the component is broken), then your meter will show 120v.