Redmine. How to change the page for creating a new task?

Question

Redmine

Good afternoon!
Please explain to the layman how to change this page in "Redmine". That is, swap the input fields and buttons in places.
This is necessary in order to quickly create tasks in the mobile version. In other words, I want the first fields to be: "To", "Subject", "Task Description" and the "Create" button, everything else is below and is optional.
The admins gave me access to the "Redmine" /opt/redmine/redmine/public folder on the server, but rummaging through it did not find the task creation page to change the input fields in the page code. Apparently there it is a little more complicated and my knowledge is not enough for this.
Thank you.

Answer 1

Additional picture from the mobile version