I'm running Laravel project on Nginx server, in which I call a python file using below command by passing arguments

$result = exec("python3 path/to/file.py $data");

In the python file, there is a line of code

    font_file = base_path+'/fonts/LiberationMono-Bold.ttf'
    cmd = ["ttf2cxf_stream",
                   "",
                   "-s","5.0",
                   font_file,"STDOUT"]
    p = Popen(cmd, stdout=PIPE, stderr=PIPE)

This is giving an error that it can't open the font file which is present on that location. The owner of the project is ubuntu:www-data and the font file is present in that project. I also tried giving it 777 permission but still no luck.

Now when I run the same command in terminal

python3 path/to/file.py "data"

It successfully runs without the font file access error. What could be the issue?