From the published simple example for ToF hat running the Micropython code below:
from m5stack import *
from m5ui import *
from uiflow import *
import time
import unit
setScreenColor(0x000000)
tof0 = unit.get(unit.TOF, unit.PORTA)
label0 = M5TextBox(85, 83, "Text", lcd.FONT_DejaVu72, 0x08feab, rotate=0)
label1 = M5TextBox(227, 174, "mm", lcd.FONT_DejaVu24, 0xFFFFFF, rotate=0)
label2 = M5TextBox(29, 31, "distance:", lcd.FONT_DejaVu24, 0xFFFFFF, rotate=0)
while True:
label0.setText(str(tof0.distance))
if (tof0.distance) < 300:
rgb.setColorAll(0xff0000)
wait(((tof0.distance) / 2000))
rgb.setColorAll(0x000000)
wait(((tof0.distance) / 2000))
speaker.sing(622, 1/16)
else:
rgb.setColorAll(0x009900)
wait_ms(2)

The statement below fails with error message

tof0 = unit.get(unit.TOF, unit.PORTA)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "unit.py", line 171, in get
File "<string>", line 1, in <module>
File "units/_tof.py", line 5, in init
File "libs/vl53l0x.py", line 119, in init
File "libs/vl53l0x.py", line 174, in _available
Unit: TOF unit maybe not connect