For setting Extensions of Fibonacci you should select the insertion menu item - "Fibonacci" - "Extension"
Extension of Fibonacci is an auxiliary tool and is used for determination of the end of the third wave, and it will be of interest only for traders who trade on the basis of Elliot's Waves
Using this tool, we can specify only level of the first wave.
After that we receive the level of the second and third wave - it is what we can see on the graphic.
Value of the first wave is accepted for one unit. Value of the second wave - for level 61.8 (rollback from the first wave). Value of the third wave - 161.8 forward from the first wave.
It is supposed that the principal changes in price should be near these levels.
These levels can also serve as support and resistance levels.