Following the documentation from https://docs.redhat.com/en/documentation/openshift_container_platform/4.19/html-single/networking/index#nw-ingress-gateway-api-deployment_ingress-gateway-api

In the section 20.12.4.1. Dedicated gateway example,

The Example dedicated Gateway resource is not copy&paste able as it lacks 

* the gatewayClass defintion

In the section 20.12.4.2. Shared gateway example,
The Example shared Gateway resource is not copy&paste able as it lacks

* the spec, which also breaks intendation
* the gatewayClass definition
* the port definition

OCP4.19

everytime

    1. follow the documentation
    2. copy&paste
    

Error "Required value" for field "spec".CreateCancel
# fixing the spec and intendation
Error "Required value" for field "spec.listeners[0].port".
# fixing the spec.listeners[]?.port 
Error "Required value" for field "spec.gatewayClassName".