Please check whether the object has subdivisions. For example. if you take the default cylinder, it has got subdivisions along its circumference, but no subdivisions along its height or length. So if you try to bend it, it won't work. Add subdivisions before you add Easy Bend. Please refer to the product document where it is explained.

Install the add-on provided on our download page. Once the add-on is installed, and you enable it, the task is taken care of automatically. Also you can add this node into a new file and save that as the default startup file. Please refer to the installation guidelines. Once set as the default startup, the node will always be available for all your future projects.

Yes. You need  to import the Bend Geometry node into your existing project or you can just install the add-on provided on our download page. Please refer to the installation guidelines on how to install the nodes for a new project or existing projects.