Reverse Proxy - SubDomain throws unsupported FastCGI protocol

I try to run InvoiceNinja throw my Reverse Proxy (SWOG), but I get a “unsupported FastCGI protocol” message. I checked the PHP Version of SWOG: 8.2
I checked the nginx config to listen on port 80 and 443.
What could be the issue?

NGINX Config:
server {
listen 443 ssl http2;
listen [::]:443 ssl http2;
#listen 80;
server_name invoiceninja.*;

root /var/www/app/public/;
index index.php;

location / {
    try_files $uri $uri/ /index.php?$query_string;
include /config/nginx/ssl.conf;

client_max_body_size 0;

include /config/nginx/proxy.conf;
include /config/nginx/resolver.conf;

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

# Handle PHP Applications
location ~ \.php$ {
    set $upstream_invoiceninja;
    include fastcgi_params;
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_pass $upstream_invoiceninja;
    fastcgi_index index.php;
    include /etc/nginx/fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_intercept_errors off;
    fastcgi_buffer_size 16k;
    fastcgi_buffers 4 16k;
    fastcgi_param HTTPS 1;
    resolver valid=30s;


Error Message:
5 upstream sent unsupported FastCGI protocol version: 72 while reading response header from upstream, client:, server: invoiceninja., request: “GET / HTTP/1.1”, upstream: “fastcgi://”, host: “”


Maybe this will help?