Hi Josie,
As Oz mentions, that control board is one of many generic designs out there, and not one that we specifically recognize.
There are some resources that may help, but there may also be some nuance to your specific one, so the only way to really do it is to try it and figure out on the go.
https://www.google.com/search?q=grbl+cnc+controller+flash+grbl
Our support team is happy to continue to help out via written communication here on the forum, but this particular topic of “how do I flash my specific controller to the latest grbl” may be getting a bit outside the realm of software support. Hopefully some of our users may be able to help, as a number of them have done this before.