E: The repository 'http://dl.bintray.com/aluxian/deb stable Release' does not have a Release file

Question

I am on Elementary OS 5.1, and due to some third party repository the above error started popping up in my AppCenter. I searched for some ways to remove repositories and found that all repositories can be found in /etc/apt/sources.list . But I could'nt find that particular repository.