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That is a SCAM page. Press Command, Option and Esc keys and this will bring Force Quit window. Select Safari and click Force Quit. This will close Safari.
Then hold down Shift key on your keyboard and open Safari. Click on Safari menu and select Clear History and Website Data. On the dropdown next to Clear, select All History and click Clear History.
(If you see Reset Safari instead, click it and Reset Safari)
That will remove that page (if you are using different browser like Chrome or Firefox), then please let me know.
Let me know how it goes please.