Hi.
If the bake ignitor is glowing but there is no flame then it's bad.
If it's not glowing check it's continuity using the multimeter.
If it's open - replace it
Part number: WB13T10045
Here are the breakdown diagrams and
Replacement parts for General Electric JGS905BEK2BB Gas range | AppliancePartsPros.com
Post the results.
Simon.