Hi @chrisroberton,
You can use the following link to setup an angular app with okta - https://developer.okta.com/docs/guides/sign-into-spa/angular/before-you-begin/
The first link you posted will be removed soon, as that guide has been deprecated.
Also, you can try a working angular sample here - https://github.com/okta/samples-js-angular
Hope this helps.