Curious if this Ignitor would be like the ones used with Barbecues (a basic Piezoelectric "snapper"), or if the Ignitor is a High Voltage Pulse device.
If Piezo, the only remedy (beside meaningless tweek time of disassembly and maybe fixing) would be to replace the Ignitor assembledge.
If HV Pulse Ignitor, verification of an operating switch, interlock(s) and High Voltage assembledge would be in order, then replacement of defective item(s).
For the latter of the cases, the HVAC trades persons would be my best guess for repair personnel.
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!