Explorer output differs between local version and the one from explore.jsonapi.dev

I am wondering, why the output of my local version is a bit different to explore.jsonapi.dev (and also to the screenshot of the project homepage). The local one does not include attribute information and the preview option for them. See screenshots:

explore.jsonapi.dev:

local (uses the local development environment lando, the Drupal Thunder distribution Version 8.x-4.3 (with Drupal Core 8.8.3), JSON:API Explorer 8.x-1.0, JSON:API Hypermedia 8.x-1.6, JSON:API Schema 8.x-1.0-alpha8):

Did I miss something during installation? Does anybody experience the same problem?