Get IOS 18 after I l've lost my backup on IOS17

Hello I have a backup on IOS 18 on my Mac, the issue is that now my Iphone 12 Pro is on IOS 17 (I deleted my IOS 17 backup)

I need to get IOS 18 back to restore the Iphone on my previous backup which is on IOS 18

Pls help me, thanksss

Get IOS 18 after I l've lost my backup on IOS17
 
 
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