PRISMA is an evidence-based minimum set of items for reporting in systematic reviews and meta-analyses. PRISMA focuses on the reporting of reviews evaluating randomized trials, but can also be used as a basis for reporting systematic reviews of other types of research, particularly evaluations of interventions.
In PRISMA 2020, there are now expanded options depending on where you search and whether you are updating a review. Version 1 of PRISMA 2020 includes databases and clinical trial or preprint registers. Version 2 includes additional sections for elaborating on your grey literature search, such as searches on websites or in citation lists. Both versions are available for new and updated reviews from the Equator Network's PRISMA Flow Diagram page.
For a step-by-step guide to completing the PRISMA Flow Diagram see this helpful guide