Timer controlled GPDMA write to GPIO

Hi.

In AN5593, How to use the GPDMA for STM32 MCUs, on page 31, it says:

"For some application needs, a timer request to GPDMA can be used to initiate a data transfer not involving timer
registers read/write, but other memory-mapped location, like for memory‑to‑memory transfers."

How exactly do I do this?

My precise use case: I have an 8*3 LED matrix, with the 8 rows connected to PA0:7. I have a uint8_t[3] of the data I want displayed and TIM8 configured at the frequency I want to update the columns at.

Thanks for the help!