User authentication process

[akhtar-gits]

I want to use user plugin to authenticate Joomla user for mobile app. My Joomla version is 3.6
I have installed com_api and installed user plugin and enabled it
created a key through com_api and tried to access the route
index.php?option=com_api&format=raw&app=users&resource=users&key=8ed6060579d49d6f919447379f5ce0b2
this url give me controller not found error http://prntscr.com/dl75a7
app = users plugin name. not sure if its correct
resource = users not sure what i have to give here
key = the key which i have created through com_api and selected the admin user while creating this key.

Please help me to sort it out. I want to login with Joomla user through my app.

Thanks in advance,