Fill the form in and give it back to your employer!
Drug tests in general aren't expensive, but your employer should be taking care of the cost for you. They're requiring it, so they should pay for it.
the company pays
I have never seen were it was not at the employer expense to have them done.
The company pays for the test if they want you to take one. They will fill out the paper work and tell you where to go to take it. Talk to them about this .. not strangers on a website.
you should have asked them