Build a REST API with API Gateway private integration: Tutorial

I am trying to work through the tutorial : Build a REST API with API Gateway private integration The question I have is about this point 5.e

Type a URL, for example, http://myApi.example.com, for Endpoint URL. Here, the host name (for example, myApi.example.com) is used to set the Host header of the integration request.

Given that an NLB with a targetgroup has been setup and a VPC link points at it. Its not clear if the endpoint here is the hostname of the EC2 that is pointed to by the NLB. Wondering if I can get a clarification on this.