Install appstream-generator by entering the following commands in the terminal:
sudo apt update sudo apt install appstream-generator
Generator for AppStream metadata
AppStream is a cross-distribution effort for creating and sharing metadata of software components available in the package repositories of a distribution. It provides specifications for an unified software component metadata format and provides tools to read, write and validate the metadata. . This package contains a tool to generate distribution metadata from package repositories. It will extract icons, download screenshots, validate and transform the metadata and return XML or YAML files that can be read by AppStream clients, such as software centers. The `appstream-generator` will also generate issue reports as JSON documents and HTML pages.