Possessive apostrophes are apostrophes (’) used with the letters at the end of a noun to show ownership over or a close connection with another noun. For example, if you were talking about the tail of your cat, you can add a possessive apostrophe and an s to show which noun is the owner.
its*
(It’s is it is)
“Its knees work hard because it’s severely overweight.”
It’s*
noun, possessive
The cat has knees. It’s knees are powder.
Here you go: It’s vs its https://www.grammarly.com/blog/commonly-confused-words/its-vs-its/
We both used links from the same source.
I’ve traditionally used no apostrophe for inanimate objects, like a bus.
But when dealing with a gendered, thinking being, use the apostrophe.
Edit: no need for down-votes for a good-faith discission, is there?