Holybro Tekko 32 ESC 1 not responding-Need Help

Newbie here and I need some help with an esc.  Have the Fettec G4 1.7 and 3 of the 4 motors will spin.  In Alpha Configurator I can see that all ESC signals are working when armed, but I'm not sure what I need to do to get the other motor to spin.  Can someone help?