If you support the Justice in Policing Act, you should call or email your two Senators and urge them to support it as well.
A number of organizations have shared scripts that can be used / adapted for this purpose. Links to these are shared below (please do not consider this an endorsement of their agenda):
If you wish, you can also draft your own message and call/email your two Senators directly. Senators’ contact information can be accessed here: https://www.senate.gov/general/contact_information/senators_cfm.cfm
Power to effect change is in your hands. Use it!