I was gifted a free share a few years ago by a mumsnetter and got an Astra Zeneca one worth £75! I still have it and it's worth more now but you can cash out whatever share you get immediately.
This is my code, open an account and deposit £1 then you'll get a free share and so will I.
It's a bit of fun and you can also withdraw your £1 if you like so it's free.
Here's my link. Please let me know what share you get, I hope it's a big one!
www.trading212.com/invite/FMO8bREA