> txpower
otbr-agent: 00:16:23.807 [D] Cli-----------: Input: txpower
otbr-agent: 00:16:23.807 [D] P-SpinelDrive-: Sent spinel frame, flg:0x2, iid:0, tid:11, cmd:PROP_VALUE_GET, key:PHY_TX_POWER
otbr-agent: 00:16:23.807 [D] P-RadioSpinel-: Wait response: tid=11 key=37
otbr-agent: 00:16:23.808 [D] P-SpinelDrive-: Received spinel frame, flg:0x2, iid:0, tid:11, cmd:PROP_VALUE_IS, key:PHY_TX_POWER, power:0
otbr-agent: 00:16:23.808 [D] Cli-----------: Output: 0 dBm
0 dBm
Done
 otbr-agent: 00:16:23.808 [D] Cli-----------: Output: Done

> txpower 100
otbr-agent: 00:22:35.043 [D] Cli-----------: Input: txpower 100
otbr-agent: 00:22:35.043 [D] P-SpinelDrive-: Sent spinel frame, flg:0x2, iid:0, tid:10, cmd:PROP_VALUE_SET, key:PHY_TX_POWER, power:100
otbr-agent: 00:22:35.043 [D] P-RadioSpinel-: Wait response: tid=10 key=37
Done

> txpower
otbr-agent: 00:23:24.620 [D] Cli-----------: Input: txpower
otbr-agent: 00:23:24.620 [D] P-SpinelDrive-: Sent spinel frame, flg:0x2, iid:0, tid:3, cmd:PROP_VALUE_GET, key:PHY_TX_POWER
otbr-agent: 00:23:24.620 [D] P-RadioSpinel-: Wait response: tid=3 key=37
otbr-agent: 00:23:24.625 [D] P-SpinelDrive-: Received spinel frame, flg:0x2, iid:0, tid:3, cmd:PROP_VALUE_IS, key:PHY_TX_POWER, power:100
100 dBm
Done