I downloaded Electrum standalone version from their website.
I am not able to run any "pip" commands in Electrum console. I have matplotlib installed in my python environment, but I can't use it inside electrum. I wasn't able to find a solution for this in the web.
Are you talking about the python version of electrum?
https://electrum.org/#download (First option here)
If you download the standalone executable (exe, AppImage, etc) then you won't be able to use the plot functionality, that's pretty much it. You can't install extra packages like matplotlib into Electrum.
This is because the standalone version doesn't allow you to install anything extra, it comes already prepackaged with whatever the devs decide, and they decided not to include matplotlib et al because it's very large. They also decided to not remove the Plot item from the menu even though it's not available. This was discussed somewhere, and they decided it was not worth the effort to do it.
It's just easier to export the wallet data and use another tool to make a plot. This probably will give you even more information anyway, as the plot functionality in Electrum is very basic.
I just made up some transactions and used the source code to emulate roughly what would be presented in an Electrum plot. It would look a bit like this:
If you're still interested in building Electrum with the plot functionality, you can follow these instruction to compile the AppImage(you would also need to make sure to add matplotlib and configure it correctly):
https://github.com/spesmilo/electrum/tree/master/contrib/build-linux/appimage