How to schedule a python script with Flask at startup

[SPRX]

Hi,
I am trying to schedule a python script with 'Flask' module import and use in the programe for Webserver. Python code (with Flsk) runs ok if you run it manually. I am running flask 2.2,  Ubuntu 18.04, Python 3.6.9 on a Jetson Nano.

It sound very simple to use CRONTAB or systemctl to schedule the program, however non seems to work with me as soon as i includ the import flask in the python code. I spent lot of time trying to figure the issue or the solution with no success.

Any suggestion/ direction on how to get it sorted if someone has come across similar issue? 

[tunk]

I think they are run in a limited shell.
If you haven't already done it, try to use full paths for commands and files.

[SPRX]

Thanks Tunk, I hv already tried that too without any luck