Did Tesco announce that everyone who shares this link will be sent a £50 voucher for its anniversary.? No, that's not true: the site is a scam that tries to steal people's data or sends them to ad-filled websites for dodgy products and offers. Don't fall for it.
The scam recently appeared on a website (archived here) named tesco.co.uk.summerpromo.win where it was published under the title "Tesco has announced that everyone who shares this link will be sent a £50 voucher for It's anniversary.". It read:
Answer a few questions for your chance to get a £50 Tesco voucher with our giveaway
To get the voucher offer you must answer a few questions first
The questions must be answered by clicking a series of buttons that do nothing. A fake confirmation message appears, followed by this message:
The "Share" button will share the scam to more people and the "Claim Voucher" button will redirect to a variety of dodgy offers and websites.
The website "summerpromo.win" was only registered (anonymously) on May 27, 2019 and has nothing to do with the real tesco.co.uk website. But by sticking that to the front of the URL the scammers made it look like they were affiliated with the real website.
Don't fall for it!