How to configure Flux for private Gitlab repository through https

I am looking for step by step documented instructions for setting up connectivity to a private Gitlab repository and configuring Big Bang to pull from that repository when installing/deploying. There are a few constraints since I am working in C2S high side. The access to the Gitlab repository must be through https (also with a proxy) as I do not have access through ssh. It is private so my understanding is that it must use a token, but I believe I also need the certificate. This should be through a service account rather than a personal account since it is installing Big Bang on the cluster.

I transferred the Big Bang 1.16.1 code base over to the classified environment as the air gap package and then added it to a private gitlab server that is available to me over https. The proxy is set in the environment variables for flux.

So far I have attempted

• creating a TLS secret with the certificate and key and then including the user and token in the repo url This gives the error: "Unable to clone ... unexpected requesting https://..." and returns 400
• creating a secret with the user and token This times out without being able to clone the repo