Santorini buses- no information on when they run to the port, help please?

I'm totally confused.

As I understand it, all buses run to and from Fira and there's a bus that runs to the port, but this official timetable mentions the price for the port buses but not the times.

https://www.ktel-santorini.gr/images/ktel.pdf

Does anyone with local knowledge know when they run?

Thanks so much