Per the help located at:
There is supposed to be an expression plotter in the Multisim Live analysis sub-palette but it's missing. Is this an error or just not a feature in Multisim Live? It's been very frustrating to find this thing.
You can find the Expression Plotter in the Analysis and Annotation section of your tool browser in Multisim Live. Please take a look at the screenshot below
What are you seeing from the Analysis and annotation tab in your end?
I just noticed with this other document that the Expression Plotter is part of the Multisim Live Premium features so it makes sense if you are not seeing this and using the free version. We are working to update that help document to make reference on how the Expression Plotter is a feature that gets active once you upgrade to Premium.
Hope you can find this useful and sorry for the confusion!