Run a script that is inside the application in the Dockerfile or during its startup

I have a script in my Next.js application that needs to be executed at runtime, and it should run as soon as the application starts. I'm unsure where I should call this script — whether from within Next.js itself or from the Dockerfile entrypoint, considering that I am deploying my application.

I also need help with how to properly invoke the script based on the most appropriate approach.

Thank you in advance for your help.