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):
https://act.everytown.org/sign/Senate_Justice_in_Policing_Act/ https://act.unicefusa.org/justice
https://act.amnestyusa.org/page/63249/data/1?locale=en-US
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!