Failure when including credentials when packaging a pip library

Question

I'm creating a pip package that must include credentials as a json file. My folder structure is like this:

.gitignore  
Dockerfile  
Jenkinsfile 
MANIFEST.in 
Makefile    
README.md   
VERSION 
credentials.json    
setup.py
bin
    __init__.py  
    config.py       
    credentials.json     
    infraestructure.py   
    main.py

I've tried adding them in the MANIFEST like this:

include VERSION
recursive-include bin/*
recursive-include bin/*.json

Also tried in the setup.py package_data with include_package_data=True as Hans pointed in this answer Including non-Python files with setup.py, to no avail, when installing the pip always return the "credentials.json not found" error. I'm don't know how to proceed that way and starting to think that the problem may be somewhere else, like when passing command to the linux terminal. Thanks in advance!