First up, log in to PlayHQ, and you should see something like the following

Under your name, you will find "My Account"

If you click on that, you should be given an option to view all of your teams under "My Teams"

Click on the team of interest, then click on "Squad"

You should now see the team squad, with singlet numbers (under the #) and if you click the > symbol (circled in red below) you will find contact information for that player.