Urgent request - My site is Down

I upload this extension (Ajax Quick Checkout FREE) for opencart 3.0.2.0
link: https://goo.gl/ZJkx5S
And want to test it in free version before buying it with full features
but it not seeming good because my site with the Arabic language
So I deleted the extension, and after that, I can't login to my site or log in to the admin control panel
and this message appears to me

Fatal error: Class 'Twig_Extension_DTwigManager' not found in /home1/mysitename/sitename/modification/system/library/template/twig.php on line 52


Note: I disconnected my store form shopunity account by mistake and can't link it without login to my admin control panel

Question: can I delete Ajax Quick Checkout FREE extension from my site from FTB and my site will work again or what's the solution

Please I need help very fast

Duplicated topic: viewtopic.php?f=198&t=199951&p=704610#p704607

Hi,

If you face any issues with our modules (anything that has a prefix of d_) then please feel free to contact us directly via support at https://dreamvention.ee/support.

Commercial or free - we will help everybody who needs it.

Enjoy!