I also read the two articles suggested to me by Phil SCARpscar13: (Just seeing the “rainbow-colored” screen on Raspberry 4 Rev 1.5 - #2 by pscar13 ). …
My English isn’t the best.
Phil SCARpscar13’s advice helped me.
I started making the mistake of connecting the micro HDMI cable1 to the wrong port (the left one).
As a beginner, it was a bit difficult for me to figure out the (well-documented) differences between the ISO image and the tar.gz image, as all the primary guides say to use the ISO image and recommend tools like Rufus.
None of the guides I know of advised me to install the tar.gz file with the Raspi Imagineer.
After installing the ISO image, I couldn’t find any of the files I needed to correct.
But after transferring the tar.gz image to the SD card with the RAS PI IMAGER and changing the HDMI port, I was able to access the configuration settings.
Currently, I still have to deal with the LAN and WAN configuration.
But since I’m apparently an exception when it comes to installing ipfire on Raspberry Pis, I apologize for any misunderstandings that may have arisen.
Best regards, Nicolai