To adjust the columns/products in a row, You must go through the following steps:
Go to your Shopify Admin Store > App > Searchly.
Click on Search & Collection Page.
Click On Customization.
Scroll down and there you will find Product Width & Height (Grid View).
Variate the height & width to increase or decrease the number of products per Row.
( Note: The variation must be in equal proportion to avoid the mess on the collection pages. )
Click on the Save button.