I am unable to type the IP Address of my plug into the "Plug to Graph" and view the power usage.
Does anybody have any suggestions on how to fix it?
If your plug(s) are detected as energy monitoring capable then the pull-down list will be populated. Since it sounds like the list is empty your plug may not have that feature built in. What model plug do you have? Otherwise, toggling the plug, opening octoprint settings and saving and then restart octoprint it might shake things loose.
I have an HS110 which does provide power usage....
Toggling the plug, opening octoprint settings and saving and then restart octoprint did not fix the problem.
I am however able to plug on and off the smartplug using the "Thunder Icon" button
Then will need to enable debug logging in the settings and check both the octoprint.log, plugin_tplinksmartplug_debug.log, and the browser's developer console for any errors.