Should I still try to file income taxes (no income or assets in Pakistan, ever but I am registered as a filer because my uncle advised me to do it a logn time ago)

I am a non-resident Pakistani living in Germany as a permanent resident (I have been living outside of Pakistan since 2017). I did not file my taxes last year as I thought since I never had any property or income in Pakistan (I have only ever earned an income in Italy or Germany) I don't need to. However, now I am not sure and want to file it. 

Unfortunately, my Pakistani number no longer works abroad and I am unable to access IRIS 2.0 (the FBR portal). What can I do in this situation? Is it possible to use my German number to register with the IRIS portal or only my email? My main concern is that FBR might try to start criminal proceedings against me and that can derail my German citizenship application 2 years from now. Maybe someone is a tax expert here and can offer some advice?