您的主应用程序中的资产目录无法从您的应用程序扩展中访问，因为它们是两个单独的应用程序包，只能共享Frameworks。

Your asset catalog in your main application isn't accessible from your application extension as they are two separate applications bundles that can only share Frameworks.

您需要在动作扩展文件夹中创建一个单独的资产目录，并在目标中引用该目录。

You will need to create a separate asset catalog in your action extensions folder and reference that one in your Targets.