Hi there!
I wanted to change the injected string to not include the URL, and changed it in the js file:
vendor/matteocontrini/flarum-imgur-upload/js/src/forum/components/UploadButton.js
//let stringToInject = `[URL=${imageLink}][IMG]${previewLink}[/IMG][/URL]\n`;
let stringToInject = `[IMG]${previewLink}[/IMG]\n`;
this.attrs.textArea.insertAtCursor(stringToInject);
Then I've re-enabled the extension and meddled with the butons on the admin panel to see if it'd update.
Still, the string did not change. Maybe I need to change it somewhere else?
As a suggestion, that could be an option too!