Unable to install Plugins

I’m trying to install geolocation plugin and Toast plugin and QRcode plugin, on every time I’m getting same error message, I can’t undersant, please fix this issue, thank you in advance.

Error: Failed to fetch plugin git+https://github.com/EddyVerbruggen/Toast-PhoneGap-Plugin.git
Probably this is either a connection problem, or plugin spec is incorrect.
Check your connection and plugin name/version/URL.
Failed to get absolute path to installed module

check plugin url for exist,
check internet connection, if use vpn check them

What is your ionic info output?

same problem for me too my ionic info is

cli packages: (C:\Users\umesh\AppData\Roaming\npm\node_modules)

@ionic/cli-utils  : 1.19.1
ionic (Ionic CLI) : 3.19.1

global packages:

cordova (Cordova CLI) : 8.0.0

local packages:

@ionic/app-scripts : 3.1.8
Cordova Platforms  : android 6.4.0
Ionic Framework    : ionic-angular 3.9.2


Android SDK Tools : 26.1.1
Node              : v8.9.4
npm               : 5.6.0
OS                : Windows 10

Environment Variables:

ANDROID_HOME : C:\Users\umesh\AppData\Local\Android\Sdk


backend : pro