Hi austinr,
Welcome to the forum.
Please follow the steps below on how to connect to 2 or 3 remote displays as separate client windows. Please note that this is not the final solution that will be available in one of the next updates and will allow connection to multiple remote monitors with a single click, opening multiple client windows automatically.
1. Start Remotly and go to Settings->General
Please find the "Max. concurrent Remotly instances" and increase it to 2 or 3. Please make sure to start the full version trial in you admin panel as the Free version limits maximum concurrent connections to one. Connecting to each display as described in this thread requires multiple simultaneous connections depending on how many remote displays will be used.
2. After enabling more than 1 concurrent Remotly instance please start Remotly again (either using desktop icon or Start menu). You should see Remotly Multi Display starting:
3. After starting Remotly Multi Display you can select which monitor will be used for connections to this instance. Please note that each instance is visible as a separate remote device and the 2nd and 3rd instance will have a _2 or _3 suffix attached to the primary instance name of this remote device.
4. On the client side please connect to both instances at the same time. You can set connection settings for each remote display independently (like framerate, scaling or bitrate). You can also connect using two different devices like a PC + tablet

In this case please use one of the devices to connect to the main remote device without any _2 suffix and the tablet to connect to the same device with _2 suffix.
Please let us know in case of any questions or doubts.