I have installed the ultimate ADs plugin and used it for my first project successfully. However, I've started with the second project now. I can see the Ultimate ADs plugin in the list of addons but when trying to add it to new project, it just doesnt appear in the list.
1st project was originally created in construct2. I had to delete the cocoon and canvas plugins from it in order to load it in construct3. Then I installed the ultimate ads plugin to it and was used successfully.