Perhaps the issue is that Certbot doesn’t know how to locate the Bitnami-managed Apache installation.
You would either need to point it using the provided flags:
apache:
Apache Web Server plugin - Beta
--apache-enmod APACHE_ENMOD
Path to the Apache 'a2enmod' binary. (default:
a2enmod)
--apache-dismod APACHE_DISMOD
Path to the Apache 'a2dismod' binary. (default:
a2dismod)
--apache-le-vhost-ext APACHE_LE_VHOST_EXT
SSL vhost configuration extension. (default: -le-
ssl.conf)
--apache-server-root APACHE_SERVER_ROOT
Apache server root directory. (default: /etc/apache2)
--apache-vhost-root APACHE_VHOST_ROOT
Apache server VirtualHost configuration root (default:
/etc/apache2/sites-available)
--apache-logs-root APACHE_LOGS_ROOT
Apache server logs directory (default:
/var/log/apache2)
--apache-challenge-location APACHE_CHALLENGE_LOCATION
Directory path for challenge configuration. (default:
/etc/apache2)
--apache-handle-modules APACHE_HANDLE_MODULES
Let installer handle enabling required modules for
you.(Only Ubuntu/Debian currently) (default: True)
--apache-handle-sites APACHE_HANDLE_SITES
Let installer handle enabling sites for you.(Only
Ubuntu/Debian currently) (default: True)
or just manually change the SSLCertificateFile and SSLCertificateKeyFile references to e.g. /etc/letsencrypt/live/example.com/cert.pem and privkey.pem .