You can use this article to upload e-books to Kobo eReader via USB Calibre setup and uploading books to Kobo
Follow this article to upload e-books to the eReader wirelessly but using Dropbox Create kobocloud with dropbox account
You can reach the eReader from the smartphone to download wireless e-books. Transfer epub from Android phone to Kobo ereader
One of the most recent questions from eReader users is that the computer does not see eReader even though it is charging. First of all, I recommend that they try to connect the device from different PCs and using different USB cables. If there is still no connection, only one way remains. Wireless e-book transfer.
The Calibre program's Wireless connectivity allows books to be transferred to the eReader without using a USB cable. Tools needed: WiFi connection, PC and Calibre installation. The connection is created by selecting "Start wireless device connection" from the "Connect / Share" menu.
Password is optional and the system is given an IP address.
After the wireless connection is created, the service becomes ready with the "Start Content server" option.
In the last case, it may be the eReader or the tablet, the IP and port information to be used to connect appears.
In the last step, the e-book to be downloaded is selected and the Download book button is downloaded to the eReader. In the simple interface, next to each book, the download confirmation window appears with the button (epub / pdf).