I don't know how to setup Ivacy VPN on your DD-WRT Router.
Follow these steps for successful configuration of VPN on Router.
1. Go to “Basic Setup” tab to your DD-WRT control settings.
2. Choose the Network type drop in the down menu & Pick “PPTP” protocol.
3. Not that “Use DHCP” should be selected as “Yes”.
4. Enter (PPTP server) provided by VPN provider
5. Enter the Email ID and Password provided by VPN
6. Write “refuse-eap” in additional PPTP option box.
7. Next, Scroll down and make sure DHCP server is “enable” and then click on “Apply Settings” and then click “Save”.
8. On the top menu click on “Status” and then click on “WAN” tab.
9. Now select “Connect” button under “WAN” tab.
Note: Ivacy VPN supports limited server locations for multiple purposes. There is no another way to connect with your desired location, except choosing an alternative VPN like Private Internet Access review
or ExpressVPN which are more reliable in these case you don't have many options.