So to access a hidden folder in home you also then need to use the personal-files interface - so you could define a personal-files plug called dot-djl-ai with write permission to $HOME/.dji.ai and then after installing the snap and manually connecting this interface your app should be able to write to this folder.
You can then request auto-connection of this so that when the snap is installed it is automatically connected and thus you should not require classic confinement.