@TZIEL 

Several options short of moving the router:

1) get a third party adapter with a longer cord with the same specs (voltage and amps)

2) get a standard extension cord or power strip (in the US, 120v AC power cord or power strip) 

3) get a 12v DC extension that has  a male and female plug the same as the router.

4) cut the cord and and add a section of wire (use solder or crimp connectors and be sure to keep the polarity correct as getting it wrong may destroy the router).

5) if you do not have a UPS, consider getting one as that would serve as an extension, protect your equipment, and have backup power. I use a UPS and plug my modem, router, phone system, and security system into it.

@ArcherC8 Thanks so much! My point is that TP-Link should make at least a 6' long power adapter cable as does the majority of other manufacturers of similar devices.

@TZIEL 

I understand that some like longer cables and others like shorter cables.

I guess I am in the other camp as I like shorter power cables as my UPS is in a cabinet right below the router, modem,... That makes for a lot less tangle of wires when you add Ethernet, USB, phone, and power cables.