Errors during build

I am getting the below errors while building, any idea what might be the issue?

"_OBJC_CLASS_$_RTCAudioTrack", referenced from:

```
_get_field_types_PhoneRTCPlugin in PhoneRTCPlugin.o
```

"_OBJC_CLASS_$_RTCEAGLVideoView", referenced from:

```
__TFC12HelloCordova14PhoneRTCPlugin15createVideoViewfS0_FT6paramsGSqCS_17VideoLayoutParams__CSo16RTCEAGLVideoView in PhoneRTCPlugin.o

__TFC12HelloCordova14PhoneRTCPlugin19addRemoteVideoTrackfS0_FCSo13RTCVideoTrackT_ in PhoneRTCPlugin.o

__TToFC12HelloCordova14PhoneRTCPlugin19addRemoteVideoTrackfS0_FCSo13RTCVideoTrackT_ in PhoneRTCPlugin.o

_get_field_types_PhoneRTCPlugin in PhoneRTCPlugin.o

_get_field_types_VideoTrackViewPair in PhoneRTCPlugin.o

__TFFC12HelloCordova14PhoneRTCPlugin12setVideoViewFS0_FCSo20CDVInvokedUrlCommandT_U_FT_T_ in PhoneRTCPlugin.o
```

"_OBJC_CLASS_$_RTCICECandidate", referenced from:

```
__TFC12HelloCordova7Session14receiveMessagefS0_FSST_ in Session.o

_get_field_types_Session in Session.o

__TTSCSo15RTCICECandidate___TFSa6appendU__fRGSaQ__FQ_T_ in Session.o

__TTSCSo15RTCICECandidate___TFVSs12_ArrayBuffer18_uninitializedCopyU__fGS_Q__FTGVSs5RangeSi_6targetGVSs20UnsafeMutablePointerQ___GS1_Q__ in Session.o

__TTSCSo15RTCICECandidate___TFVSs12_ArrayBufferg9subscriptFSiQ_ in SessionDescriptionDelegate.o

__TFC12HelloCordova7Session14receiveMessagefS0_FSST_ in Session.o

_get_field_types_Session in Session.o

__TTSCSo15RTCICECandidate___TFSa6appendU__fRGSaQ__FQ_T_ in Session.o

__TTSCSo15RTCICECandidate___TFVSs12_ArrayBuffer18_uninitializedCopyU__fGS_Q__FTGVSs5RangeSi_6targetGVSs20UnsafeMutablePointerQ___GS1_Q__ in Session.o

__TTSCSo15RTCICECandidate___TFVSs12_ArrayBufferg9subscriptFSiQ_ in SessionDescriptionDelegate.o
```

"_OBJC_CLASS_$_RTCICEServer", referenced from:

```
__TFC12HelloCordova7Session4callfS0_FT_T_ in Session.o

__TTSCSo12RTCICEServer___TFSa6appendU__fRGSaQ__FQ_T_ in Session.o

__TTSCSo12RTCICEServer_PSs9AnyObject____TFSs15_arrayForceCastU___FGSaQ__GSaQ0__ in Session.o

__TTSCSo12RTCICEServer___TFVSs12_ArrayBuffer18_uninitializedCopyU__fGS_Q__FTGVSs5RangeSi_6targetGVSs20UnsafeMutablePointerQ___GS1_Q__ in Session.o
```

"_OBJC_CLASS_$_RTCMediaConstraints", referenced from:

```
__TFC12HelloCordova14PhoneRTCPlugin19initLocalVideoTrackfS0_FT_T_ in PhoneRTCPlugin.o

__TFC12HelloCordova7SessioncfMS0_FT6pluginCS_14PhoneRTCPlugin21peerConnectionFactoryCSo24RTCPeerConnectionFactory6configCS_13SessionConfig10callbackIdSS10sessionKeySS_S0_ in Session.o

__TFC12HelloCordova7SessionCfMS0_FT6pluginCS_14PhoneRTCPlugin21peerConnectionFactoryCSo24RTCPeerConnectionFactory6configCS_13SessionConfig10callbackIdSS10sessionKeySS_S0_ in Session.o

_get_field_types_Session in Session.o

__TFC12HelloCordova14PhoneRTCPlugin19initLocalVideoTrackfS0_FT_T_ in PhoneRTCPlugin.o

__TFC12HelloCordova7SessioncfMS0_FT6pluginCS_14PhoneRTCPlugin21peerConnectionFactoryCSo24RTCPeerConnectionFactory6configCS_13SessionConfig10callbackIdSS10sessionKeySS_S0_ in Session.o

__TFC12HelloCordova7SessionCfMS0_FT6pluginCS_14PhoneRTCPlugin21peerConnectionFactoryCSo24RTCPeerConnectionFactory6configCS_13SessionConfig10callbackIdSS10sessionKeySS_S0_ in Session.o

_get_field_types_Session in Session.o
```