Passing request headers using fastcgi in Nginx

I have quit a few API's that use Oauth (not Oauth2). We are moving all of our sites from Apache to Nginx (using fastcgi) and I am running into an issue with request headers not being sent. I have read numerous posts and the Nginx docs and I am still not able to get the header params to pass through.

I am using Postman to make API requests and setting these headers:

I did finally manage to get the key of the header to show up when I var_dump($_SERVER); but I cannot get the actual value to pass through.

Here is my main nginx.conf http block:

http {
    include mime.types;
    default_type  application/octet-stream;

    sendfile on;
    keepalive_timeout  6000;
    client_max_body_size 128M;

    gzip  on;
    gzip_comp_level 5;
    gzip_min_length 256;
    gzip_proxied any;
    gzip_vary on;

    gzip_types
    application/atom+xml
    application/javascript
    application/json
    application/rss+xml
    application/vnd.ms-fontobject
    application/x-font-ttf
    application/x-web-app-manifest+json
    application/xhtml+xml
    application/xml
    font/opentype
    image/svg+xml
    image/x-icon
    text/css
    text/plain
    text/x-component;

    include /Users/webdev2/.valet/Nginx/*;
    include servers/*;
    include valet/valet.conf;
}

And here is my valet.conf:

server {
    listen 80 default_server;
    root /;
    charset utf-8;

    location /41c270e4-5535-4daa-b23e-c269744c2f45/ {
        internal;
        alias /;
        try_files $uri $uri/;
    }

    location / {
        rewrite ^ /Users/webdev2/.composer/vendor/laravel/valet/server.php last;
    }

    location = /favicon.ico { access_log off; log_not_found off; }
    location = /robots.txt  { access_log off; log_not_found off; }

    access_log off;
    error_log /Users/webdev2/.valet/Log/nginx-error.log;

    error_page 404 /Users/webdev2/.composer/vendor/laravel/valet/server.php;

    location ~ \.php$ {
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass unix:/Users/webdev2/.valet/valet.sock;
    fastcgi_pass_request_headers on;
    fastcgi_pass_header Authorization;
    fastcgi_pass_header http_oauth_token;
    fastcgi_pass_header oauth_token_secret;
        fastcgi_index /Users/webdev2/.composer/vendor/laravel/valet/server.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME /Users/webdev2/.composer/vendor/laravel/valet/server.php;
        fastcgi_read_timeout 300;
    }

    location ~ /\.ht {
        deny all;
    }
}

And finally, here is my fastcgi_params file:

fastcgi_param QUERY_STRING  $query_string;
fastcgi_param REQUEST_METHOD  $request_method;
fastcgi_param CONTENT_TYPE  $content_type;
fastcgi_param CONTENT_LENGTH  $content_length;
fastcgi_param SCRIPT_FILENAME  $request_filename;
fastcgi_param SCRIPT_NAME  $fastcgi_script_name;
fastcgi_param REQUEST_URI  $request_uri;
fastcgi_param DOCUMENT_URI  $document_uri;
fastcgi_param DOCUMENT_ROOT  $document_root;
fastcgi_param SERVER_PROTOCOL  $server_protocol;
fastcgi_param GATEWAY_INTERFACE CGI/1.1;
fastcgi_param SERVER_SOFTWARE  nginx/$nginx_version;
fastcgi_param REMOTE_ADDR  $remote_addr;
fastcgi_param REMOTE_PORT  $remote_port;
fastcgi_param SERVER_ADDR  $server_addr;
fastcgi_param SERVER_PORT  $server_port;
fastcgi_param SERVER_NAME  $server_name;
fastcgi_param HTTPS   $https if_not_empty;
fastcgi_param REDIRECT_STATUS  200;
fastcgi_param HTTP_PROXY  "";
fastcgi_param HTTP_AUTHORIZATION $http_authorization;
fastcgi_param OAUTH_TOKEN $http_oauth_token;
fastcgi_param OAUTH_TOKEN_SECRET $http_oauth_token_secret;

Here is an image of the response of the var_dump($_SERVER). NOTE: This var_dump is before anything else in the app gets called.