on Apple products you can only use Safari to install PWAs.
OSX there's a little button that will add it to the Apps folder.
On iOS you must open with safari and use the share > add to homescreen.
On windows it can be installed as a "chrome app" the button for that appears in Chrome address bar.
on any other device that is not apple you can use chrome to create your own installation experiences leveraging the 'beforeinstallprompt' event listener
Apples mistreatment of PWA is unfortunate, as of this writing they are facing a class action lawsuit over it. add to homescreen does install the PWA installation but the process/messaging has been made deliberately confusing.
Until that is resolved if there is an issue with customer education on apple devices the only real option is to wrap it up with something like electron or capacitor.