Undefined symbols for architecture arm64 - Unity Ads

I am using Unity Ads from Asset Store (since the internal ad sdk has a bug that prevents ads to show on iOS (works in editor though)). But when I try to build in xcode I get below error. I searched all over the internet, nothing works. Please help!

 Undefined symbols for architecture arm64:
   "_UnityAdsIsReady", referenced from:
       _Platform_UnityAdsIsReady_m3224219300 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_IsReady_m1940034296 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsIsReady_m3224219300)
   "_UnityAdsSetMetaData", referenced from:
       _Platform_UnityAdsSetMetaData_m1790711249 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsSetMetaData_m1790711249)
   "_UnityAdsSetDidInitiatePurchasingCommandCallback", referenced from:
       _Platform__ctor_m334176308 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsSetDidInitiatePurchasingCommandCallback_m845104069 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsSetDidInitiatePurchasingCommandCallback_m845104069)
   "_UnityAdsSetDidStartCallback", referenced from:
       _Platform__ctor_m334176308 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsSetDidStartCallback_m3797837678 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsSetDidStartCallback_m3797837678)
   "_UnityAdsShow", referenced from:
       _Platform_UnityAdsShow_m3373951341 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_Show_m4129900215 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsShow_m3373951341)
   "_UnityAdsGetVersion", referenced from:
       _Platform_UnityAdsGetVersion_m2243661488 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_get_version_m3854020257 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsGetVersion_m2243661488)
   "_UnityAdsInitialize", referenced from:
       _Platform_UnityAdsInitialize_m282382030 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_Initialize_m3310767589 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsInitialize_m282382030)
   "_UnityAdsSetReadyCallback", referenced from:
       _Platform__ctor_m334176308 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsSetReadyCallback_m451768802 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsSetReadyCallback_m451768802)
   "_UnityAdsPurchasingDispatchReturnEvent", referenced from:
       _Platform_UnityAdsDidInitiatePurchasingCommand_m3816664491 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsPurchasingGetProductCatalog_m2180521046 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsPurchasingGetPurchasingVersion_m618922504 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsPurchasingInitialize_m1149165094 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsPurchasingDispatchReturnEvent_m1880679472 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsPurchasingDispatchReturnEvent_m1880679472)
   "_UnityAdsSetDidErrorCallback", referenced from:
       _Platform__ctor_m334176308 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsSetDidErrorCallback_m3205639914 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsSetDidErrorCallback_m3205639914)
   "_UnityAdsSetDidFinishCallback", referenced from:
       _Platform__ctor_m334176308 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsSetDidFinishCallback_m386922261 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsSetDidFinishCallback_m386922261)
   "_UnityAdsSetGetProductCatalogCallback", referenced from:
       _Platform__ctor_m334176308 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsSetGetProductCatalogCallback_m1834361531 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsSetGetProductCatalogCallback_m1834361531)
   "_UnityAdsSetGetVersionCallback", referenced from:
       _Platform__ctor_m334176308 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsSetGetVersionCallback_m858406520 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsSetGetVersionCallback_m858406520)
   "_UnityAdsSetInitializePurchasingCallback", referenced from:
       _Platform__ctor_m334176308 in Bulk_UnityEngine.Advertisements.iOS_0.o
       _Platform_UnityAdsSetInitializePurchasingCallback_m3878818099 in Bulk_UnityEngine.Advertisements.iOS_0.o
      (maybe you meant: _Platform_UnityAdsSetInitializePurchasingCallback_m3878818099)
 ld: symbol(s) not found for architecture arm64
 clang: error: linker command failed with exit code 1 (use -v to see invocation)