Version 1.13 is not yet available. Instead of hitting refresh I suggest periodically checking the downloads. When 1.13 shows up there then more than likely it will show up in the updater.
/e/ image ROM download - ginkgo
EDIT:
Ah, I forgot, the ginkgo is listed as one of the devices that so far has missed 1.13.
Note the comment from Manoj…
The team did extract a list from the image servers of all builds that did not get v1.13. Will share the information as to how we will be handling these builds… Releasing with v1.13 or v1.14.