I’m sorry, there doesn’t seem to be an ‘infinity’ symbol on my keyboard.
How to type an infinity symbol (∞) using the keyboard:
On Windows (10) – hold the ALT key and type 236 on the ‘num lock’ keypad.
On a mac – Hold the Option key and press 5
It is more complicated on an iPhone as you have to make a keyboard shortcut.
Being a scientist in my day job I have to use the symbol quite regularly!