Both forms are acceptable:
fruit(s) of your labor - definition and synonyms
PHRASE
the benefits of your hard work
It’s an efficient lawn mower that leaves you time to enjoy the fruits of your labor.
https://www.macmillandictionary.com/us/dictionary/american/f...Specifically:
When one uses "fruit", it means a single fruit like mango, orange, and so on. But when we use "fruits" it refers to different kinds of fruit; for example "there are fruits in the basket" means that there is more than one type of fruit in the basket. Fruit is an uncountable noun, so it has no plural form.
https://english.stackexchange.com/questions/25147/is-using-f...