The Alfawise U 30 is a single extruder machine.
Therefore you dont need "T0" in the starting script; deactivate the line by typing a ";" in front of T0 or delete it.
Nevertheless T0 must be definited as the First temperature identifier in Tab Temperature of the settings window.
And also the extruder motor and the temp-sensor must be connected to their T0-pins on the mainboard.
T0 ist the name of the first Temperature Identifier what is identical with "First Extruder" , when a machine is equiped with two extruders (dual-extruder) the 2nd one is named T1
To switch between them, T0 and T1 is also a command. E.g. comming from T1 the "T0"-command in front of a command line, switches all following commands to the T0 -extruder so that it works. To reactivate the 2nd extruder, "T1" in front of a command line switches to it ... until the next "T0".
Have a look to the attached picture. This refers to a similar Anet A 8 machine.