Why lsb_release -c command , returns n/a?

recently I switched from **zorin os** to **deepin 20** for it's outstanding UI and eases of use for daily operations. it's almost OK but if I need some newer packages which are not listed in official deepin repositories, I have to use some community installer scripts that rely on this command to obtain the correct linux LSB version :

-c

the problem is : **the return value is "n/a"** that consequently, breaks down the installation process. how can I fix this ?