If your TV is off or disconnected from Wi-Fi, EVVOLI cannot turn it on (unless your TV supports Wake-on-LAN, which many lower-end models do not). For that, you still need the physical remote or an IR blaster accessory.
To pair the app, your TV must already be on and connected to Wi-Fi. If you’ve completely lost your remote and your TV is off, this app won’t help you initially.