‘What happens in Vegas is supposed to stay in Vegas’

“The final countdown!!” Usher sings in his best metal-wannabe wail of the 1986 Europe hit “The Final Countdown.”

And indeed it is, now just hours from Usher Raymond IV, 45, to play perhaps the biggest stage of his life: The Super Bowl LVIII halftime show at Allegiant Stadium in Las Vegas.

But, as he stresses to The Post from rehearsals, he’s not sweating it.

In fact, Usher even makes time to give us an exclusive photo shoot rocking his own blinged-out accessories, including his trademark “U” necklace, his own personal Super Bowl ring and a custom handmade Dolce & Gabbana football encrusted with scores of Swarovski crystals.

This is a man who has been preparing for this moment for 30 years — since he released his self-titled debut as a 15-year-old in April 1994.

“You know, this has been an amazing year ramping up to this,” said Usher of his “My Way” Las Vegas residency that finished at the Dolby Live-Park MGM in December after 17 months and 100 shows.

“It definitely helped to play 100 sold-out shows, in preparation for the Super Bowl,” he added. “Now, obviously, a much bigger audience. And the 200 million people that will be watching probably adds a bit of pressure, but . . . I’m ready, man. I’m now just in preparation to enjoy it.”

When you’ve had such monster No. 1 hits as 1998’s “Nice & Slow,” 2001’s “U Remind Me,” 2004’s “Yeah!” and 2008’s “Love in This Club” — plus a brand-new album, “Coming Home,” out Friday — the biggest challenge isn’t execution.

“You know, the hardest part was really crafting it — not actually doing it,” said Usher. “Because 12 minutes is not a lot of time to squeeze in 30 years, you know what I’m saying?”

And with his hot Vegas residency having made him the biggest stud in Sin City — it became the ultimate girls’ trip destination after Usher serenaded Kim Kardashian for all of social media to see in April 2023 — he was a natural choice to lead the mid-game throwdown between the Kansas City Chiefs and the San Francisco 49ers.

Jay-Z and his Roc Nation company — producers of the halftime show since 2019 — couldn’t deny the obvious after Usher practically serenaded the underwear off everybody from Keke Palmer to Janelle Monáe during his residency.

“After having this year in Las Vegas, I’m like, ‘I don’t know if Jay-Z is going to have another option,’” said Usher matter-of-factly.

“I thought, ‘I get it. I understand why you want me to do it. It’s really good of you as a curator to understand that.’”

While back in the day when Wayne Newton was known as Mr. Las Vegas, the glitzy city was considered a haven for has-beens, that is no longer the case, with everyone from Adele and Lady Gaga to U2 having recent residencies.

But none of those A-plus-listers came close to steaming up the scene with their audience participation like Usher.

“I like to have a good time,” he said. “I don’t want anybody to, you know, get in trouble. But if you [do], they say what happens in Vegas is supposed to stay in Vegas.”

Now, after being a special guest when the Black Eyed Peas were the headliners in 2011, Usher is getting to have his own Super Bowl moment.

“Luck favors the prepared, and sometimes patience can be rewarded so long as you are steadfast in what you believe,” he said.

And Usher has been patient with himself in waiting to release “Coming Home” — his first solo album in eight years — until he was good and ready.

“Though I had gone through a lot of experiences that I felt were interesting and gave me some really cool topics and things to talk about and share, I just didn’t feel like I was ready to share a full body of work yet,” he said. “There were some things that needed to be worked out, and I feel like now is the time.”

Certainly, it will be Usher’s time come Super Bowl Sunday.

“This is a legacy moment — and a legacy moment that has given me the opportunity to celebrate in a place that I call a home away from home: Las Vegas,” he said. “It’s just like home to me now.”