To convert the code from the GitHub repository you provided into a format that is compatible with Firefox, the following steps could be taken:
Replace instances of "chrome" with "browser" in the code. In the Chrome extension API, the "chrome" namespace is used to access various features and functionality, but in Firefox, this namespace is replaced with "browser". Therefore, all instances of "chrome" in the code would need to be replaced with "browser" to ensure that the code is compatible with Firefox.
Replace any references to Chrome-specific APIs with their Firefox equivalents. The Chrome extension API includes a number of features and APIs that are specific to Chrome, and these would need to be replaced with the corresponding Firefox APIs in order to ensure that the code is compatible with Firefox.
Update the manifest file to use the correct format for Firefox. The manifest file is a JSON file that specifies various metadata and configuration information for the extension, and the format of this file is different for Chrome and Firefox. Therefore, the manifest file in the code would need to be updated to use the correct format for Firefox.
Test the code to ensure that it is functioning properly in Firefox. Once the code has been converted and updated to be compatible with Firefox, it would be necessary to test the code to ensure that it is functioning properly in Firefox and that all of the desired features and functionality are working as expected. This may involve installing the extension in Firefox and testing it with a variety of inputs and scenarios to ensure that it is working properly.
Overall, these steps would involve significant modifications to the code in order to make it compatible with Firefox. However, by following these steps and carefully reviewing and testing the code, it should be possible to convert the code