If you are deploying Casdoor on an Intranet, you may not be able to access the static resource directly over the Internet. You need to deploy static resources where you can access them, and then modify the configuration in Casdoor in 3 places.
Deploy static resource
All static resources in Casdoor, including images, logo, css, etc., are stored in casbin/static repository.
Clone the repository and deploy it on a web servers. Make sure you can access the resource.
Modify in Casdoor
You can simply modify the configuration file to set the static resource address to where you deployed it. Go to conf/app.conf, set
staticBaseUrl to your deployed address.
staticBaseUrl = "https://cdn.casbin.org"