This is not how the integrations works, you need to have an Elastic Agent running on a host that you manage to receive the data.
Then on this Elastic Agent you add the F5 integration, this integration will be the HTTP endpoint that you configure your F5 to send the metrics according to the documentation.
On Elastic Cloud you will have only Elasticsearch, Kibana and a Integrations Server, this integration servers can run a Fleet Server to manage your elastic agents or an APM server.
Every other integration that needs to collect or receive data needs to run on an agent hosted somewhere else, this is not managed by Elastic.