Checkout process needs to be optimized for Desktop and Mobile.
Desktop Screenshots and flow below.
Select Product >> Direct to Checkout >> Shipping Details [login to view URL] >> Order review and Payment Method [login to view URL] >> Upsell Page [login to view URL] >> Confirmed...
Like this mobile steps will also be provided.
This plugin should only be enabled from Magento CMS Landing page as there will be only one product in the cart.