Install iPad beta OS from PC or Mac

My iPad doesn’t have enough space to install OTA updates. I have to use a PC or MAC. But since apple dropped iTunes, the replacement app won’t show or allow update to a beta OS. It beta shows on my iPad, but when I attach it to the Mac, it says the software is up to date and won’t show the option to install the beta. Any suggestions?

Install iPad beta OS from PC or Mac
 
 
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