How can I transfer my iTunes library from iPad wirelessly?

Sorry, not possible. There is no way to transfer music form the Music App on one iPad to the Music App or nay other app on another iPad.

You need a computer to sync the music or use the iCloud Music option.

If the music is not available on a computer at all, then you will need to extract it from the source iPad.

click here ➜ Recover your iTunes library from your iPod or iOS device - Apple Community

There are no native tools available to achieve your aim. Your iTunes Music Library, located on a Windows PC or Mac computer, can be synchronised with your iPad - but you will require the original computer upon with the Library is stored to do so.

If the original computer upon which the iTunes Music Library is stored is not available, there are third-party software packages available that can copy the Library between devices. A popular option for PC and Mac is iMazing - easily found with a Google search.