If you have a proxy, virtual private network (VPN), or remote desktop program (RDP) running on your device, you won't pass the geolocation checks necessary to use DraftKings. Examples of RDPs are Bomgar, TeamViewer, Remote Desktop Viewer, and Zoom.
Even within the US, FanDuel may not be available in certain states, which could block you from placing bets while traveling. You can use a VPN to get an IP address from a state where FanDuel operates legally. This will let you regain access to your FanDuel account and enjoy betting while on the move.