无法在实体框架中为ApplicationUser创建外键

Package manager is throwing errors when trying different things. I want to create a foreign key to 'ApplicationUser' entity in my 'YogaSpace' entity. I've looked at multiple different threads online to see how to accomplish this and I think my code first code is correct. Here is what I've done and here is the error I'm getting in package manager when updating the database.Package manager is throwing errors when trying