Is this using a built-in SmartThings Device Type Handler or a community developed device type handler? If it’s a community DTH, can you share the link to the relevant community post?
If the Thermostat/Valve doesn’t include at least one of the capabilities that we support (Temperature Measurement, Valve, Thermostat, etc), but it at least supports one of the generic ‘Actuator’ or ‘Sensor’ capabilities, then you may be able to authorize it manually: