How should we handle the certificate when we create a python app which gets and sends data on https server?

The python script uses Urllib3 and my server is scripted on Node.js. I’m worrying (and not understanding clearly) about the certificate: Do I need to save as variable the certificate on my python app?

For example I did this,

http = urllib3.PoolManager(
    cert_reqs="CERT_REQUIRED",
    ca_certs='client-cert.pem')

and I don’t know if this is the right way to do it, like it is secure way to do it, or it’s okay if hacker gets the hands on certificate?

I successfully set up python app with Node.js in that way as I explained, I’m expecting the hacker to not get hands on the data being sent and recieved by app and server.