This simple extension allows you to add Image and Link without typing markdown code. It will show a pop-up in which you have to enter Title and URL and Click OK and you are done.
composer require ramesh-dada/flarum-gui-image-and-link
composer update ramesh-dada/flarum-gui-image-and-link
composer remove ramesh-dada/flarum-gui-image-and-link