Styling checkout and missing link "Back to shop" for headless channel Checkout

[hynekk]

Hello,

we are having couple issues with the checkout. We have implemented custom cart operations on our website using Storefront API. All works as expected except couple things around checkout:

1. When user goes to checkout URL that is generated by storefront API all cart content is presented but there is no link back to shopping. When user is coming from online store then the link back to shop is presented.

   1. How can I tell the checkout url that there is link to go back to? For example https://mytesteshop.myshopify.com/checkouts/cn/c1-blablabla/information?returnUrl=blabla.com/products/
   2. 

2. I would like to add couple lines of css to change font and do some additional styling as setting in shop for checkout is not enough.

   1. 

I read that there used to be solution via checkout.liquid but modifying this via theme is deprecated now (https://shopify.dev/docs/themes/architecture/layouts/checkout-liquid). That says we are supposed to upgrade to Shopify Plus to be able to modify checkout process etc.

Do we have to upgrade to Shopify Plus to be able to change these to simple things? Is there any other way around this? Biggest issues is number one not having ability for user to go back as only remaining way is back button in browser.

Thank you

[hynekk]

styling cannot be done until upgraded to Shopify Plus as discussed here https://community.shopify.com/topic/522262

[lvbn]

Basically, there is no way to change the default buttons from checkout and thankyou page without upgrading to Shopify plus?

Any ideas on how I can use this button to redirect the user to my custom storefront instead of redirecting the user to the theme store?

Any help is much appreciated!