In <https://wiki.ubuntu.com/Networking#settings-connections> I suggest that there should be a "Prompt whenever a new connection requires Web login" checkbox, and that one of the occasions for prompting should be immediately after checking the checkbox. So even if it was already checked, unchecking then re-checking it would be a moderately guessable way of polling on demand.
In <https:/ /wiki.ubuntu. com/Networking# settings- connections> I suggest that there should be a "Prompt whenever a new connection requires Web login" checkbox, and that one of the occasions for prompting should be immediately after checking the checkbox. So even if it was already checked, unchecking then re-checking it would be a moderately guessable way of polling on demand.