An advert I saw recently referred to a hairdressing salon and “it’s high standards”. It should not have used the apostrophe.
When do you use the apostrophe?
“It’s” is short for “it is”. You insert the apostrophe to show that you are missing out the i from “is”.
“Its” refers to something belonging to someone or something else. If you were describing the features of a house, you could say: “Its front door was green.” You do not insert the apostrophe.
So insert the apostrophe to shorten the phrase “it is” and leave it out to denote possession.
It’s that simple. There’s no need to worry about the apostrophe and its uses.