LoRa packet-Forwarder doesn't start

I can confirm that the repositories that you are using are correct.

made connections to my IC8808 board

I think you mean the IC880A-SPI? iC880A-SPI - LoRaWAN Concentrator 868 MHz | LoRa Concentrators | Wireless Modules | IMST GmbH. Did you see this manual? https://wireless-solutions.de/images/stories/downloads/Radio%20Modules/iC880A/iC880A-SPI_QuickStartGuide.pdf

Did you see this section in the manual?

2.2.2 Preparing the Reset Pin Control

Also this note could be related to your issue:

The power pins (21, 22) have to be connected to a power source that is able to provide more than 700 mA. Therefore it is recommended to choose a proper power supply that is able to supply the iC880A-SPI and the host system (e.g. Raspberry PI) at the same time.

Hope this helps.