Equations in Keynote in a browser

I am trying to see if I can add equations in Keynote in iCloud via browser (I don’t have a Mac/Iphone). I searched but couldn’t find a way other than copy-pasting an image from somewhere. (I’m using Chrome, and I couldn’t do it neither in Linux nor in Windows)

A similar question is about sub/super-scripts. I could not find a way to insert them either in a browser.

Keynote: change the font of an equation

I’m using the built-in equation tool in Keynote. Is there a way to change the font used by default in Keynote?

Also, I see that when I try to use text in the equation via \text{} the font is in bold mode. How can I change that?

Note that a relevant Keynote question has been asked here.

As an example for the font change see this picture enter image description here

As an example for the bold text see the picture which was generated by \Gamma \text{ is fixed}

enter image description here