Set arm_solution to corexy or hbot in config, for example, add this line to your configuration file :

arm_solution      corexy

Then uncomment corexy_homing in config if using homing

Also it is recommended to set

alpha_max_rate
beta_max_rate

to the top speed your steppers can go, as these refer to the actuator speed (the X and Y steppers) which on a corexy can run nearly twice as fast as the requested Cartesian speed when going in certain directions.

Movement in the X direction or Y direction always involves both alpha and beta motors. This can make it confusing to configure a corexy solution. If you find that after wiring and configuring your printer that movement is wrong, then these possible solutions may help: