The documentation states very clearly that the route should look like this:
For the GraphQL endpoint, enterhttps://<my_domain.com>/api/2019-07/graphql, where<my_domain.com>is the domain of your shop. The domain must be either aconnected domainor your shop's<shop>.myshopify.comdomain.
Unfortunately when using any version specific endpoint, such as this
The browser issues the following errors
When using the following route, however, everything works fine.