Hi @shizart, we are sad to hear that you experienced issues with enabling/using our plugin. There is a video linked to the plugin description explaining how it works. Here is a link for your convenience. The plugin works only in the edit mode for pages/post and other supported elements.
There is a free version of the plugin that doesn’t require any key to get started. You just install the plugin on your WordPress website and it’s ready to use. To check how it works, you need to open any post or page for editing. And as soon as you do it, you should see red underlines for words that aren’t recognized by spelling engine.
Could you please give us a bit more information on the steps that you took and how you tested the solution to come up to the conclusion that it did nothing? Since you mentioned that you subscribed to the trial on our website, you are welcome to reach our support email address and our support team will do our best to help you in using the plugin.