Correct spelling

gets

Correct spelling, explanation: gets is third person singular form of the verb get in present simple tense. An apostrophe before s is used to abbreviate the word is or to express possessiveness, so it cannot be used with verbs. This is why get’s is a mistake and gets is the correct form.

Definition of gets:
verb, third person singular form of get; to receive something, to become
Michael always gets angry when I buy new clothes.
A person who wins the contest gets a video game.


Incorrect spelling

get’s

Incorrect spelling, explanation: this form doesn’t exist because apostrophe with s after it is used with nouns (for example to express possessiveness). Get is a verb and gets is its form for third person singular in present tense. Therefore get’s is incorrect.