Where can I find the extensions directory?

Guys, I have some trouble finding the extensions directory in Plone5 to add my external method . I need to place a python script in that directory.

Add something like next line to your instance section in buildout.cfg

zope-conf-additional = extensions ${buildout:directory}/Extensions

make a directory Extensions in your buildout directory and rerun buildout

Using External Methods is completely deprecated (although still working). Use brower views instead.