How to access proxy from my docker container

How do I connect to my Proxy from the container. I am trying to deploy Nginx plus using Debian images on docker host. Dockerfile will update the Debian and Install ngnix plus on images.

Receiving below error while running the Dockerfile. How do I setup the Debian image to access debian url behind the proxy,

Err:1 stretch InRele
initiate the connection to (200
connect (101: Network is unreachable) [IP:
2001:4f8:1:c::15 80]