You should add the license into metadata for the asset pack(s):
"Edit asset pack->Metadata->Release Info->License for assets" It will increase the size of audience that will be able to find your art
You can leave a comment here to support my proposal about making metadata visible for those who are interested in it https://itch.io/t/2919128/metadata-encouragement#post-7952450
Hello! I also recommend you to upload it to OGA (OpenGameArt).
-Who are they?
It is a platform like itch but only for assets and only licensed under one of free-culture licenses. They would like to have your assets because they are really quality! ;)
- How will it help you?
They allow links in the description and people that view assets on OGA usually open links to itch to support creator on other platforms... So it can increase count of views on itch and spread your assets between bigger audience.