After updating extension.js along the lines of https://askubuntu.com/questions/1286212/no-js-module-tweener-found-in-search-path-gnome-shell-extension-error-on-ubun, there is still an error with a "No property x_fill on StBin" error.
- Bug#994062: gnome-shell-extension-tilix-dropdown: No JS module 'twe... Ted To
- Bug#994062: Acknowledgement (gnome-shell-extension-tilix-dropd... Ted To