I'd take a leaf out of a conversation I once had with a partner for inspiration to answer this question. For him, innovation meant finding new ways of doing an established task/process. It didn't
need to include technological or business-minded innovation at all (and this came from a person whose firm won many awards consecutively for their innovation, btw).
With this in mind, the trick to answering this question lies in thinking deeply about instances where you have had to find a way to do something differently, where you have had to adapt to your circumstances to efficiently produce a result, complete a task or undertake a process.
Once you understand this, trust me, the examples will start flowing out. A time when you've had to work within a tight budget to produce a high-quality piece of work, how you finished a task in the event of a technological failure, how you delegated tasks within a team to get them done quickly, when you instituted a new process at work/uni/society to bring efficiency to the way things were being done- the list really is endless.
Once you've picked an example, the focus must shift towards demonstrating your innovative thought process
and the impact of your actions. The structure could look something like this-
state the example

state why you needed to be innovative

walk through the choices you made to make to bring about innovation in said example

what was the impact of your actions on the task/result/process/.