How to output a conditional count of items on a chart?

I have a spreadsheet, which has information filled in by a number of people with a date when this information was added, something like this:

Person Title     Researcher     DateData engineer    Adam           05/06/22CEO & Founder    Jack           06/06/22Co-founder       Jack           07/06/22AI engineer      Adam           07/06/22ML engineer      Jack           07/06/22

What I need to do is to output the amount of leads that Jack has found on a specific day, count them and put it into a graph. I know how to get that information with a formula, but it looks like COUNTIFS doesn't work in graphs.