WP Manga FTP Storage
The FTP Storage add-on allows you to upload chapter images to any external servers which support FTP connect. After installed, it will create an additional settings panel in WP Manga Storage settings page
These settings can be taken from your FTP server. For example, we use Bunny CDN service. It is a CDN, but it provides FTP access. Once sign up, you will find settings for Storage Zone and Pull Zone. Imagin that Storage zone is the “Storage Path” setting and Pull Zone is the Domain setting in the above screenshot.
The FTP & API Access tab will give you settings you needed, while the Pull Zone give you a default Hostname to use. In this example, madara.b-cdn.net.
So whenever you upload an image using FTP Storage and above settings, the image URL will be something like “https://madara.b-cdn.net/madara/manga_xxx/chapter-1/1.jpg”
Although the above example is for BunnyCDN, you can use FTP Storage for any FTP Server to server as your CDN.