Glow coil yes, heat no

Trying to diagnose the old tumble but no heat problem on this gas dryer. I’ve noticed the glow coil comes on intermittently then goes away. Is this normal or should it stay on? Also, should I see a flame at some point because I don’t. Thanks all for any help!

If the glow coil comes on, and then shuts off and no gas, you need to replace the coils on the gas valve. Tom ApplianceEducator.com