NginX reverse proxy settings

Questions
1

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

server {
    listen 80;
    server_name my.website.ca;  

    location / {
        proxy_set_header X-Real-IP $remote_addr;
        proxy_pass https://another.website.com;
}

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

thanks for any help!

Mike