php - DbQuery() class and T_OBJECT_OPERATOR

I need to connect a list of subscribers to a website that deals with newsletters, called newsman. The website is on prestashop, so I searched for a module to do the work, and found this: https://github.com/Newsman/PrestaShop-Newsman. I downloaded it. uploaded it to the prestashop website, but I got an error:

Syntax error, unexpected T_OBJECT_OPERATOR`

So I started dabbling with the code and found that the issue is:

$q = (new DbQuery())
->select('`email`')
->from('newsletter')
->where('`active` = 1');

which I modified to this:

$q = new DbQuery();
$q->select('`email`')
->from('newsletter')
->where('`active` = 1');

After these changes, I was able to install the module, had access to it, but pressing the synchronize button( which calls a function that contains this bit of code from above) didn't do anything, so I guess I didn't really solve anything.

What can I do to solve this? And what is DbQuery? I cannot seem to find anything about this class online? I worked with SQL queries before, but never with this class and the structure of the query seems weird to me.