If you wish to NOT store the phpBB db credentials into the WP database, it is possible to use the custom phpBB config.php file inclusion and use it in this way:

if not done already because you want to use custom files for shortcodes etc, create the folder

/wp-content/plugins/wp-w3all-custom/

add into the new created wp-w3all-custom folder the file

/wp-content/plugins/wp-w3all-phpbb-integration/addons/phpBB_config.php

after you opened it with a text editor and filled with proper phpBB db connection values.

So you’ll have /wp-content/plugins/wp-w3all-custom/phpBB_config.php

In this way the integration plugin will work using the file db credentials.

NOTE IMPORTANT: you have to setup by the way the phpBB URL param into the plugin admin (this will be soon changed/simplified).

NOTE ALSO that there is no requirement to activate the option USE CUSTOM FILES so to have this to work.

If the file

/wp-content/plugins/wp-w3all-custom/phpBB_config.php exist

it will be used. This can be useful and come in help for several scenarios.

For example: setting up wrong database connection values and falling with WP into a critical error because running in debug mode, it is possible to provide the custom config file that will be used in place of stored DB values as first choice if the file exist.