@wala.beliah
Firstly, you can try importing the .idf file with the AFN back into OpenStudio. However, at the time of writing, I'm not sure if OpenStudio can read airflow networks from .idf files.
None the less I suggest that you try this first.
Currently the Building Components Library website appears to be down, I do believe that there is an example measure or components there with Air flow networks. Please check back later to take a look. This is a good starting point if you cannot import the .idf into OpenStudio.
Alternatively I suggest that you check out the pollination discord there should be some examples of using the OpenStudio SDK to build up a airflow network there in a measure.
Lastly you can try to build a measure using the OpenStudio SDK yourself at: https://openstudio-sdk-documentation....