https://docs.google.com/forms/d/e/1FAIpQLScJBMZx6EN5Lc72SUnGbP9GlMFsN0nvczA6RTjpza-dCoSfJw/viewform
Also:
https://www.whitehouse.gov/contact/
Aaaand: The Senate hasn't voted yet (not that I expect them to do anything but force the settlement on the workers) but you may phone the United States Capitol switchboard at (202) 224-3121. A switchboard operator will connect you directly with the Senate office you request.