I saw that some photographers have been able to test with models through modelwire.com and would like to know how to do this? I saw no place to upload a portfolio but have gotten "permissions" from some agencies, now I'm just not sure how to contact them for tests. Any help is much appreciated

modelwire.com is a platform that many agencies use to send model packages to photographers and clients. You can register as a photographer and then send permission requests to agencies so you can view their boards and you can message the bookers through the system.

Modelwirenetwork.com is a place for freelance models, MUA's, stylists and photographers to meet, similar to here on MM.

Same company owns them but they are two different platforms. Unless you're shooting for the agencies a lot or booking models for clients already modelwire.com wont be of much use. It's really a booking platform and not a networking platform like modelwirenetwork.com.  But the traffic and volume on the network site is very minimal.

When they accepted you (granted you permission for viewing their boards), you should have received an email. That email has the booker's name and email address that granted you the permission.
You can call (preferable) or email, expressing your interest in testing.

Thank you both so much for the help!!

Thanks for the explanations in here. I was clueless as well. lol.