NginX reverse proxy settings

I have a real simple Nginx set up to mask where I’m sending the user as follows:

server {
    listen 80;

    location / {
        proxy_set_header X-Real-IP $remote_addr;

I set up SAML using Okta on, but unsure what I need to add in my configuration such that the SAML information is pass properly to the as the Auth break for me.

thanks for any help!