str_time = input("What time is it now?")
str_wait_time = input("What is the number of hours to wait?")
time = int(str_time)
wai_time = int(str_wait_time)

time_when_alarm_go_off = time + wait_time
print(time_when_alarm_go_off)

NameError: name 'wait_time' is not defined on line 6

In this example, there are a number of typos to fix. The first one is identified as wait_time is not defined on line 6. Now in this example you can see that there is str_wait_time on line 2, and wai_time on line 4 and wait_time on line 6.