Agree, we should add the links on the main site so it's clearer. But, it seems like a step back if you need to use figma file or github to search when you can use our app.
The figma plugin works on my end. I've asked the dev team to look into it but in the meantime can you recheck on your end if the error persists?
https://github.com/webalys-hq/streamline-vectors/blob/main/R...
https://www.figma.com/community/file/1063138616574654762
We still recommend using the app just because we keep improving icons frequently.