How to Update iPad Pro 1st Gen 10.5 to iPadOS 18 ??

I purchased an older iPad (OS 17,7.) to access some unique music making tools that are tragically imprisoned in iOS Alcatraz. One app that would be fun to revisit is Garage Band, but it App Store installation now requires iPadOS 18+.

A 2024/03 Mac Observer article says 1st Generation 10.5″, 1st – 4th Generation 11″, and 2nd – 6th Generation 12.9″ can all be upgraded to iPadOS 18. However, my device's [General/] Software Update page reports that it is "up do date" and doesn't offer any further OS updates.

Any way to bend the prison bars enough to let iPadOS 18 in?? -- OR --

Any way to get a slightly earlier version of Garage Band on a perfectly functional iPad sporting 17.7.9 ??