iOS limits websites based on the options you've selected and their own algorithms to determine sites safe for general users and for accounts used by minor children. If the site you are attempting to access is marked as restricted you will receive a message indicating "You cannot browse this page because it is restricted."
Note that the "Allow Website" link may not work, particularly if the device is identified as belonging to a minor child.
Great Hearts cannot support your iOS device or its settings. We recommend that scholars use only the Chrome browser, and do not use the Canvas Student app for either iOS or Android. (See TX and AZ Technology requirements.) Please see the Apple support site for additional information.