Led light always on. Furnace will not do a thing

Sorry first time on this site. I have a goodman gmt090-3 will not light . I put my volt meter on black to ground red to flame sensor fan starts up blower runs will not ignit, or open gas valve

If the inducer motor is coming on,the next step should be the igniter will glow, then the gas valve opens ,the burners flame up. If the igniter does not come on and glow, carefully remove and inspect for cracks and /or dark discolored spots,, the igniter is very fragile you don`t want to break it