CORS failure in Dashboard-Template

Hello guys,

I'm trying to implement a web-based terminal in my node-RED-dashboard with the template node. For this I am using xterm and now I want to connect it to wetty. But always I'm connecting it to the socket, the following error-message is visible in the console-tab:

Access to XMLHttpRequest at '' from origin '' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

I've already read, that I have to configure the Access-Control-Allow-Origin with Express and Cors but I cant figure out how to add the library to the dashboard-template-node.

Here you can see the node:


Thanks in advance