If you live outside the US and are unable to access The CW App or CWTV.com, it is because The CW has streaming rights only in the United States since it's a US broadcaster.
Even though The CW isn't available in your country, however, there might be another station there showing the program you're looking for. Please take a look at your local listings to see. Then you might find out that they have an app too.
When does the new season of my favorite CW show start?