Shopify => Buy Button redirect to checkout. (Recharge Subscription Compatible)

I have a product page, that also offers subscriptions through Shopify. I want to send users to checkout page directly after they add products to cart. I tried to use "window.location.href = '/checkout';" however for subscription product it does not work.

I have a sidemenu where I have a checkout button and that works to send to Recharge checkout, I wish to mimic that logic for my Buy Button