Step 1 - Go to the "Powertools" section and click "Forum" icon.
(see screenshot)

Step 2 - Choose destination directory (could be subdomain). Leave empty if you want to install directly in the main directory. Choose database, database user (the database should be created before installing the PHPBB Board) and file owner. Further specify site title, site description, administartor name, email and password.
(see screenshot)

IMPORTANT: If you choose already used database, its content will be wiped out for the new content. Also note that PHPBB board takes 6MB of disk space!
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the images!!!

If you have more question regards this matter, please contact our
support team