Reference to the unstable area of the Beckhoff repository

In the next step, the Sources list must be modified so that packages are obtained from an unstable area of the Beckhoff repository during the development phase. To do this, the package source must be changed so that it refers to this unstable area.

Open the bhf.list file with the following command:

sudo nano /etc/apt/sources.list.d/bhf.list 

Change the existing entry by adding -unstable:

https://deb.beckhoff.com/debian trixie-unstable main

When apt is executed with the command apt update or apt install, it attempts to connect to the Package Server to obtain packages. In this case, apt checks the authentication files under /etc/apt/auth.conf.d/ to see whether login data is available for a server.

If the data is available and correct, apt automatically establishes the connection and can download packages from the Beckhoff Package Server.