Help with nginx configuration

server {
    listen 80 default_server;
    listen [::]:80 default_server;

    server_name _;

    # Redirect all HTTP requests to HTTPS
    return 301 https://$host$request_uri;
}



# Blocking requests not coming from the domains
server {
    listen 443 ssl default_server;
    listen [::]:443 ssl default_server;

    server_name _;

    # SSL configuration for default server block
    ssl_certificate /etc/letsencrypt/live/st-kan-selfhost.dev/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/st-kan-selfhost.dev/privkey.pem;

    # Deny all requests to unknown server_name over HTTPS
    return 403;
}


...


server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;

    # Domain
    server_name im.mydomain;

    # SSL keys
    ssl_certificate /etc/letsencrypt/live/mydomain/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/mydomain/privkey.pem;

    # allow large file uploads
    client_max_body_size 50000M;

    # Set headers
    proxy_set_header Host              $host;
    proxy_set_header X-Real-IP         $remote_addr;
    proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;

    # enable websockets: http://nginx.org/en/docs/http/websocket.html
    proxy_http_version 1.1;
    proxy_set_header   Upgrade    $http_upgrade;
    proxy_set_header   Connection "upgrade";

    # set timeout
    proxy_read_timeout 600s;
    proxy_send_timeout 600s;
    send_timeout       600s;

    location / {
        proxy_pass http://wireguard-ip:2283;
    }

}