Apache reverse proxy to docker container

I have a website running on a docker container, and I've created a VirtualHost on the host's apache that is doing a reverse proxy to the container (on host's 8280 port). So I have:

<VirtualHost *:443>
    ServerName www.example.com
    DirectoryIndex index.php index.html
    SetOutputFilter SUBSTITUTE,DEFLATE

    ProxyPass / http://localname:8280/
    ProxyPassReverse / http://localname:8280/

    Substitute "s|http://localname:8280/|https://www.example.com/|i"

    SSLEngine on
    SSLProtocol all -SSLv2
    SSLCipherSuite ALL:!ADH:!EXPORT:!SSLv2:RC4+RSA:+HIGH:+MEDIUM:+LOW
    SSLCertificateKeyFile /path-to/privkey.pem
    SSLCertificateFile /path-to/cert.pem
    SSLCertificateChainFile /path-to/chain.pem

    <Proxy *>
        Order deny,allow
        Allow from all
        Allow from localhost
    </Proxy>
</VirtualHost>

<VirtualHost *:80>
    ServerName www.example.com
    ServerAlias www.example.com

    Redirect permanent / https://www.example.com/
</VirtualHost>

Proxy works well, I have a response when writing www.example.com in the browser, but I have all the links pointing to http://localname:8280 (as shown in the browser console) and a mixed content error, that's why I've put the Substitute directive, but it is not working.

I am using configuration for mod_substitute from apache documentation.

https://httpd.apache.org/docs/2.4/mod/mod_substitute.html

But this is not working, anything changes. The docker container is based on bitnami/apache image with default configuration.

Any help would be appreciated.

Ok, I have found the answer by myself. You only have to add the following line over Substitute directive:

AddOutputFilterByType SUBSTITUTE text/html