a now OUTDATED httpd/Apache vhost to run PeerTube | note that only Nginx is supported by the PeerTube team, and with this or any other Apache configuration, you will likely get NO SUPPORT.

peertube.conf

# requires WebSocket support with `a2enmod proxy_wstunnel`
# check https://ssl-config.mozilla.org/#server=apache&version=2.4.41&config=modern&openssl=1.1.1d&hsts=false&ocsp=false&guideline=5.6 for hardening security

<VirtualHost *:80 [::]:80>
        ServerName peertube.example.com
        ServerAdmin webmaster@example.com
        Protocols h2c http/1.1

        RewriteEngine On
        RewriteCond %{REQUEST_URI} !^/\.well\-known/acme\-challenge/
        RewriteCond %{HTTPS} off
        RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

        Alias /.well-known/acme-challenge/ /var/www/certbot/
        <Directory /var/www/certbot>
                Options None
                AllowOverride None
                ForceType text/plain
                RedirectMatch 404 "^(?!/\.well-known/acme-challenge/[\w-]{43}$)"
                Require method GET POST OPTIONS
        </Directory>

        ErrorLog "/var/log/httpd/peertube.example.com.error.log"
        CustomLog "/var/log/httpd/peertube.example.com.access.log" common env=!dontlog
</VirtualHost>

<VirtualHost *:443 [::]:443>
        ServerName peertube.example.com
        ServerAdmin webmaster@example.com
        Protocols h2 http/1.1

        SSLEngine on
        # For example with certbot (you need a certificate to run https)
        SSLCertificateFile /etc/letsencrypt/live/peertube.example.com/fullchain.pem
        SSLCertificateKeyFile /etc/letsencrypt/live/peertube.example.com/privkey.pem

        Header always set X-Content-Type-Options nosniff
        Header always set X-Robots-Tag none
        Header always set X-XSS-Protection "1; mode=block"

        # Bypass PeerTube webseed route for better performances
        Alias /static/webseed /var/www/peertube/storage/videos
        <Location /static/webseed>
                # Clients usually have 4 simultaneous webseed connections, so the real limit is 3MB/s per client
                SetOutputFilter RATE_LIMIT
                SetEnv rate-limit 800

                SetEnvIf Request_Method "GET" GETMETH=1

                Header set Access-Control-Allow-Origin "*" env=GETMETH
                Header set Access-Control-Allow-Headers "Range,DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type" env=GETMETH
                Header set Access-Control-Allow-Methods "GET, OPTIONS" env=GETMETH
                SetEnvIf GETMETH "1" dontlog

                SetEnvIf Request_Method "OPTIONS" OPTIONSMETH=1

                Header set Access-Control-Allow-Origin "*" env=OPTIONSMETH
                Header set Access-Control-Allow-Headers "Range,DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type" env=OPTIONSMETH
                Header set Access-Control-Allow-Methods "GET, OPTIONS" env=OPTIONSMETH
                Header set Access-Control-Max-Age "1000" env=OPTIONSMETH
                Header set Content-Type "text/plain charset=UTF-8" env=OPTIONSMETH
                Header set Content-Length "0" env=OPTIONSMETH
        </Location>

        <Location /videos/embed>
                Header unset X-Frame-Options
        </Location>

        ProxyPreserveHost On
        ProxyTimeout 600

        # Websocket tracker
        RewriteEngine On
        RewriteCond %{HTTP:Upgrade} websocket [NC]
        RewriteRule /(.*) ws://127.0.0.1:9000/$1 [P,L]

        <Location />
                ProxyPass http://127.0.0.1:9000/ timeout=600
        </Location>

        ErrorLog "/var/log/httpd/peertube.example.com.error.log"
        CustomLog "/var/log/httpd/peertube.example.com.access.log" common env=!dontlog
</VirtualHost>

I'm on so many different repo and work that I think you are right, PT works as default with a reverse proxy... even if it certainly can work without proxy ;)