The chat box is more than a plain text field. There is a formatting toolbar along the top, so you can write a properly structured message, paste in code, or type maths that renders correctly.
What the buttons do
H1, H2, H3. Headings, for breaking a long message into sections.
B and I. Bold and italic.
Bullet list and Numbered list.
Code. A code block, which keeps indentation and uses a monospace font. Useful for anything the tutor needs to read literally.
Table. Inserts a table you can type into.
Inline math (xₙ). An equation that sits inside a line of writing.
Block math (∫). An equation on its own line.
Writing maths
Both maths buttons open an editor where you type LaTeX. If LaTeX is not your thing, the symbol picker covers the common ones. The equation renders properly in the message, so the tutor reads what you actually meant.
The other buttons
Below the text box, + attaches a file, the microphone dictates, and the waveform starts a voice conversation.