My 3 year old daughter doesn’t want to share her toys and play with other ppl. Even when the parents take her book she will take away and cry loudly. I’m afraid she will grow up with no friends and loner.

How do I teach her to share with other ppl and play together?

get a 2nd kid then u can make her understand more. if she is a single child. it will hard for her to learn.
u buy something and share with her too

you need to expose her to other kids.

Only child? got cousins? bring her over to play with them more often

First of all, you must understand that you will not achieve anything if you make she play with other children.
She is already 3, she can talk a bit. Try asking why she does not want to share her toys.
Best of all, if you show her that playing with someone is much more fun. Play with her, build castles, come up with stories, make her interested in playing with you and other people.
In the end, there is nothing terrible in that she does not share, this may be a feature of her character. You must treat this with understanding.
Every time she is near other children, try to kindly explain to her that the toys will be in safe if she shares them, and kids will definitely turn them back