Since version 1.4.7 it’s possible to self-host the amcharts library, to avoid using their CDN to fetch the necessary files.
By default the plugin does not include the maps library and amcharts core files, since they take more than 100mb.
Using Pro Version
If you’re using the Pro version, you need to follow these steps:
Download Amcharts4 Library and Geodata Files
You will need to visit amcharts.com/download and download both Amcharts 4 and Amcharts 4 Geodata zip files.
Upload to your server
You will need to upload the contents of each zip file into a folder in your server/website. You will need to use FTP or other method. The contents should be unzipped. You should end up with the following structure:
Set the URL
Once you have the files online on your website, in the settings page of the plugin, in the amcharts tab, you can add the full URL to the folder where you placed the files:
After you save the settings, your maps should fetch the necessary files using the new URL path.
Using Free Version
Currently this is not possible to do in the free version.