Google Spreadsheets-remove from window

Look what i marked in the red color, thats very annoying because its in the way for me. How to remove that??

remove.png

This is a feature of Google Sheets.
It occurs when you scroll away from the cell you are typing in.
It can not be turned off.

If you have finished looking in a cell, the "fix" (macos) is to click the esc key.
If you have finished typing in a cell, the "fix" is to hit the Enter/Return key to finalise input of the formula.

If you have NOT finished typing, then you cant get rid of it, but you can scroll up/down or change to another tab so it doesn't get in the way so much.