Here's another useful tip.
Say you do have a Mac, but unfortunately it's too old to install the recent Xcode of which you need the iOS SDK to build and publish your app.
The workaround is to simply download the latest Xcode installer archive from Apple in the form of a .xib file, then extract it on your Mac (you'll get a Xcode.app with a greyed icon because your Mac won't be allowed to run it); move it in your Applications folder anyway, and run the builder's Migration Assistant. It'll make no difference and everything will happen as if that version of Xcode was actually installed on your Mac.
Happy building,
:: @Pierre-Marie Baty added on 03 Jun ’23 · 11:22
*edit* Download links to Xcode .xib files : https://xcodereleases.com