InstaBrute Errors (Help!!)

Hi Everyone im a noob and i have been trying to use instabrute but i get the following errors

Using 1 seconds of delay

Traceback (most recent call last):

File "instaBrute.py", line 142, in

main()

File "instaBrute.py", line 132, in main

driver = webdriver.Firefox(profile)

File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/firefox/webdriver.py", line 144, in _init_

self.service.start()

File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/common/service.py", line 81, in start

os.path.basename(self.path), self.starterrormessage)

selenium.common.exceptions.WebDriverException: Message: 'geckodriver' executable needs to be in PATH.

Could someone please help me out.