"no such image" installing DuckDNS

Hi all,
I’m running hassOS on a rasperby pi 3 model b.
After a few days of setting up I think I’ve got everything how I want it with the exception of duckDNS add-on.
I had it installed through supervisor but it wouldnt start up (either manually or on restart) I couldn’t get to the bottom of that so I uninstalled it and attempted to reinstall it.
Now it wont let me reinstall. It gives me a pop up with unknown error and tells me to check the logs where I then find

20-10-04 13:28:38 INFO (SyncWorker_2) [supervisor.docker.interface] Pull image homeassistant/armv7-addon-duckdns tag 1.12.1.
20-10-04 13:28:50 ERROR (SyncWorker_2) [supervisor.docker.interface] Can’t install homeassistant/armv7-addon-duckdns:1.12.1 -> 404 Client Error: Not Found (“no such image: homeassistant/armv7-addon-duckdns:1.12.1: No such image: homeassistant/armv7-addon-duckdns:1.12.1”).
20-10-04 13:28:50 INFO (SyncWorker_2) [supervisor.docker.interface] This error is often caused by not having enough disk space available. Available space in /data is: 25.4 GiB

From trying to find similar posts on the forum I’ve seen mention of using portainer to check for having it installed twice as a potential solution to starting problem- I’ve done this and cant see any mention of it in containers or images.

To someone not so familiar with these things I would think that installing would be how the image gets onto my system, not a thing that stops the installation. Is there another way to put the image where it needs to be?

edit: installation of other add-ons seems to be fine, so presumably its something to do with having previously had it an uninstalled?

Could you see any addon or home assistant containers?

The a setting to unhide them - that I have forgotten how to do.

EDIT: I should have finished reading your post.

Hi Tom,
Yes it does show containers (and images) for the add ons for portainer and samba along with some others, but not for DuckDNS