The developers of the Google Stadia application faced a similar problem as the developers of the GeForce Now service. In order to enter the iOS market, application developers had to deal with special regulations established by Apple, which prohibit the release of applications that allow for playing in the cloud. This does doesn't, however, that Apple completely blocks developers from accessing their platform when it comes to streaming games. Google Stadia has received permission to operate via the Safari web browser. As a result, Google Stadia is now available in 22 countries and owners of iPhones and iPads can already get access to this service.

To use Google Stadia, you must have iOS or iPadOS version 14.3 on your devices. So far, Google Stadia is available in 22 countries. They are: United States, Canada, Great Britain, France, Italy, Germany, Austria, Spain, Sweden, Switzerland, Denmark, Norway, Finland, Belgium, Ireland, Netherlands, Poland, Portugal, Czech Republic, Slovakia, Romania and Hungary.

source