@Earmas21, you can either set up your new network to match the last network the TV connected to (same SSID/network name and password) or get a physical remote. The app won't help until the TV is connected to the same network as the phone. You can get a cheap universal remote that supports Roku TVs or the $10 simple TV remote from Roku.
Roku TV Remote | Replacement Remote For Roku TV | Roku
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