Pretty sure theres a flame sensor in the model
youre talking about .
It would be retained by a 1/4” sheetmetal screw
On left hand side of burners

What error code ( blinks ) are you getting ?
Its on the circuit board , lower panel of furnace.
Should might be a sight glass on lower panel .

If not youll have to remove lower panel
Rig safety switch to close so you can see the board with panel off - and wait for the furnace
to go through it sequence to observe error code .