OPRE's webpage about the study is [here][1].
Click [here][2] to access the main page for the study’s approved Office of Management and Budget (OMB) Paperwork Reduction Act (PRA) package. Under "View Supporting Statement and Other Documents," you can access information about the evaluation plans, including data collection instruments.
[1]: https://www.acf.hhs.gov/opre/research/project/evaluation-of-the-national-human-trafficking-hotline-program
[2]: https://www.reginfo.gov/public/do/PRAViewICR?ref_nbr=202007-0970-012