adding a CR definition like this one:

apiVersion: capabilities.3scale.net/v1alpha1
kind: API
metadata:
creationTimestamp: '2019-12-11T18:21:50Z'
generation: 1
labels:
environment: testing
name: example-api
namespace: appdev-api-management
resourceVersion: '2940793'
selfLink: >-
/apis/capabilities.3scale.net/v1alpha1/namespaces/appdev-api-management/apis/example-api
uid: 19ab2392-1c43-11ea-9002-064766189734
spec:
description: api01
integrationMethod:
apicastHosted:
apiTestGetRequest: /
authenticationSettings:
credentials:
apiKey:
authParameterName: user-key
credentialsLocation: headers
errors:
authenticationFailed:
contentType: text/plain; charset=us-ascii
responseBody: Authentication failed
responseCode: 403
authenticationMissing:
contentType: text/plain; charset=us-ascii
responseBody: Authentication Missing
responseCode: 403
hostHeader: ''
secretToken: MySecretTokenBetweenApicastAndMyBackend_1237120312
mappingRulesSelector:
matchLabels:
api: api01
privateBaseURL: 'https://echo-api.3scale.net:443'

doesn't create an API in the API Manager (neither Product nor Backend).