The NHS Test Kit text scam below with a link to omicron.id-51.com is a scam. The fake Omicron ID-51 text, which claims recipients have been in contact with someone who has the Omicron variant and they must order a free PCR testing kit, is being sent by scammers. But, omicron.id-51.com is a fake and phishing website that steals personal and financial information.
The The Omicron ID-51 Text Scam
NHS: You have ben in contact with someone who has recently tested positive for the COVID-19 Omicron Variant. You are required to order a test kit via: omicron.id-51.com
The link in the fake NHS text message go to the fraudulent website: omicron.id-51.com:

On the fraudulent website, visitor will be asked to submit personal and financial information.

If the requested information is submitted, it will be sent to the scammers who will use it fraudulently.