Changing ggplot box plot legend title

[Grace_Bradley]

tukeyboxplot(data = data_long_labels,
y = score,
x = job,
by = affect) + (labs(x="Job Status", y="Attractiveness Score"))

My code. Im struggling to change the title of the by = affect from affect to Facial Expressions.
Searched it a lot on the web and have figured out have to change every other label but not this one.

[FJCC]

Assuming that the by argument maps to ggplot's fill aesthetic, it would be done like this in ggplot

ggplot(data = data_long_labels,
             aes(y = score,
             x = job,
             fill = affect)) + 
  geom_boxplot() + 
  (labs(x="Job Status", y="Attractiveness Score", fill = "Facial Expression"))

If by maps to color, change the labs argument to color.