Library problem

hello everyone,
i am facing a problem when i try to deploy my flask application into (OVH public cloud sandbox ubuntu) server. First of all i could run a simple flask API with a hello world text on it, However when i try to run a flask API with keras model the page stays on loading and i don't receive any error messages.
the problem seems to happen when i import keras or tensorflow, Thus i have this library installed on the ubuntu server with the similair versions as i had in my local machine (2.4.1 for tensorflow, 2.4.3 for keras, 3.6.9 python).
Note : when i put import keras as a comment the API load in a normale way.