I keep getting a pop up from apple-alert-online.com and theres no way to close the tab without closing all windows. Does anyone have a solution for this or a way to block this website on safari?

Every time i try watching a specific show from an online website, the "apple-alert-online.com" pop up appears and its impossible to close the tab without closing the entire window. I'm looking for either a way to block this website completely on safari or any solution that anyone can offer so that i can still watch movies from that website (never had problems before today), without having to close the whole window every time this particular pop up appears.