Create Chrome or Firefox extension with keyboard shortcuts

Hello,

There is a website I use a lot. The page has:
- a calendar
- two input fields
- a submit button

I need the extension to do the following:
- clicking on "A" key of the keyboard: select the date 30 on the calendar
- clicking on "B" key of the keyboard: insert the number 10 in the second input field
- cliking on "C" key of the keyboard: click on the submit button

I cannot provide password to the website as it is IP allowed, but we can work on teamviewer.

Thanks