在URL中添加access_token GET参数可确保被允许查看页面图像的用户能够看到它(在这种情况下为18yo ++).但是，我还没有找到一种通过API确定某些用户何时或为什么无法访问页面的方法.

Adding the access_token GET parameter to the url makes sure users who are allowed to view the page image will see it (18yo++ in this case). I have, however, not found a way to, through the API, determine when or why pages are not accessible by certain users.