The portal-backend has been moved and this repository is now deprecated. You can find the code at the new location:
https://github.com/catenax-ng/tx-portal-backend
If you want to check out previous versions of the code just open the according release version. The last state in main is the following:
https://github.com/catenax-ng/product-portal-backend/releases/tag/move-to-tx-portal-backend