Add to cart not working

[bigboss97lnt]

I added the extension folder to /App/Code/lillik, then I ran php bin/magento setup:upgrade then backend configuration appeared and I enabled it then selected show decimal: yes , Decimal Length: 3 then I Saved it, flushed cache.
Front end is perfect everything has 3 decimal points as expected but when I press add to cart button it refreshes the page and doesn't add it to cart. It use to add to cart directly without refreshing.
PS: Couldn't run php composer.phar require lillik/magento2-price-decimal as it takes so much ram and VPS doesn't have much.
Using Magento 2.3.6 btw

Thanks anyways, regards
Nasser