When users join a guest WiFi service through a captive portal, they have the opportunity to enroll in a Passpoint service by downloading a profile onto their device. However, the process for downloading a Passpoint profile may vary depending on the operating system due to differences and limitations in the captive portal's "mini-browser."
Android
In Android, users are presented with the option to enroll in Passpoint before the network authentication during their access journey. Thanks to a recent Android update (retroactive since Android 10), the "WiFi mini-browser" in Android now supports over-the-air downloading and provisioning of Passpoint profiles. The user experience is illustrated in the image below.
Here you can see a video of the end-to-end experience.
Note: Android is working on an upgrade that will allow devices to automatically switch to the Passpoint network once the profile has been downloaded, further simplifying the user experience
iOS
For iOS devices, the CNA ("captive network assistant") allows downloading a Passpoint profile but also forces the closure of the CNA before the user is actually authorized on the network. For this reason, the advised experience is to prompt the user to download the profile after the network authorization, on the landing page (that on iOS devices remains open in the CNA). The resulting user experience is depicted in the following image.
Note that on iOS, the user also has to finalize the activation of the profile in the Setting app.
Here you can see a video of the end-to-end experience.