Extension does not work in Firefox with third party cookies disabled

[h-five-e]

To login the extension wants to read cookies from https://api.raindrop.io/v1/raindrops/links but can't because third party cookies are disabled. I get this log in the extension debugger:

Request to access cookie or storage on “https://api.raindrop.io/v1/raindrops/links” was blocked because we are blocking all third-party storage access requests and content blocking is enabled.

When enabling third party cookies, the extension works and is logged in, but only until I disable 3rd party cookies again. I would appreciate a fallback where the extension uses it's own storage to store a session cookie when it can't access the one on the website.