The most straightforward way. Plug in your phone, drag the IPA into the tool, and enter your Apple ID to sign it.
Are you planning to install this on a device or a stock iOS 15.0 phone?
Once you find the .ipa file, you cannot simply "download and run" it on an iPhone like a computer program. You will need a sideloading utility:
The filename indicates (Universal) and "64bit" , which is standard for modern devices. However, ensure the "ok15" tag refers to compatibility with your specific firmware. If the app was designed for a much older version of iOS, it might "thin" or crash on launch due to missing modern frameworks. 4. Safety First