Before installing the One Click Trading and Level2 Plugin, please set up the trading platform for ECN/Crypto trading.
You can download the latest version of the One Click Trading and Level2 Plugin on the official website: TRADING > Platforms > Trader's tools. 

Download the OCTL2P installation file.

Please close all running applications before installing the plugin (including all MT4 terminals).

Run the installation file. In the setup window, click Next.

Read and accept the terms of the agreement.

Select the MetaTrader 4 folder as the Destination Folder. Click Install to start the installation process.
Note: The plugin will be installed to the default destination folder if you have already installed MT4 ECN - FXOpen.

When the installation process is complete, you can choose whether you want to launch the terminal. Click Finish to exit the setup.