Error: EACCES: permission denied, open '../650427186662080513.txt'

getting error like this

The codes :

Please help!

Hello, can you please tell us the output of
If you are running this without changing the directory this error will be expected because you cannot write to the file “/{id}.txt” which is one directory up from the default /app directory. Instead I would recommend you write to the current directory with a single dot or the .data directory.

I dont know what is that, can you help me by checking around my project ?