Exporting data from Piwik

I am looking for some references on how the data exporting works in Piwik.

What we are trying to do is to grab the data visitors for a specific campaign/keyword group. We believe there is something very fishy with the bounce rate from that particular ad campaign and that the advertiser may be messing with us so we are collecting data on every visit.

Any help is greatly appreciated.

grab the data visitors for a specific campaign/keyword group.

Use a Custom Segment Segmentation - Compare segments of visitors - Analytics Platform - Matomo
or use the API: Segmentation - Compare segments of visitors - Analytics Platform - Matomo