I am being ask this question often; therefore, I am posting the answer here.
Commonly there are those who wish to do a process that normally is asynchronously, such as performing AJAX operations in a synchronous fashion. There are a few ways to do this.
You can use either prom-client or epimetheus.
Something to considered is that some of the metrics display by epimetheus and prom-client differ.
Express Gateway use express. I tried different swagger packages; however, the closest results was to display all the endpoints from the admin side of Express Gateway.