Sorry, our current version of the extension is broken in Firefox. This bug is being fixed and it works fine on Google Chrome

Hi Asif, we are currently working on the extension and a new version would be updated. There may be some issues with the image blocking and we are trying to build a new and better model. Please check out the next release. This is a community driven project and it is facing some limitations. Thank you for sharing it with us. Would you mind creating an issue at https://github.com/nsfw-filter/nsfw-filter/issues