I went through the ‘Build a Shopify App with Node and React’ tutorial:
https://shopify.dev/tutorials/build-a-shopify-app-with-node-and-react
and the result doesn’t work in Safari 13.1 – I get into an endless redirect loop. So I suspect the ‘koa-shopify-auth’ library needs to be patched.
I wrote up how we fixed our apps:
We don’t use either of the Shopify-provided libraries since our apps have a .NET Core (C#) backend but I hope this help others.