Running club selection for NYCRUNS race

I’m new here, so apologies in advance if this is an easy one…

I’m signed up for NYCRUN’s Firecracker 10K on 6/29 (my first ever race!). On the registration page, there is a field to select my running club affiliation. There are many NYC-based running clubs available in the dropdown list, but Endorphins doesn’t seem to be one of them. There is an option to have a form sent to your club’s leadership team to have it added to the list, but I thought I should probably float the question here first…

1) Why is Endorphins not listed?

2) What is the benefit of registering with a running club affiliation?

Thank you!

-Greg