500 error when setting up directory protection with mod_authn_dbd

Question

I'm trying to use mod_authn_dbd to password protect a directory.

I used the code from their apache help page, but it's chocking on the DBDriver line

# mod_dbd configuration
DBDriver mysql //modified
DBDParams "dbname=mydbname user=myuser password=mypass" //modified

/path/to/folder/.htaccess: Invalid command 'DBDriver', perhaps misspelled or defined by a module not included in the server configuration.

The documentation says Please note that you need to load an authorization module, such as mod_authz_user, to get it working. but I have no idea how to do that.

Any idea how to fix this?