Undefined symbols for architecture x86_64: \"_OBJC_CLASS_$_WKWebView\", referenced from: ld: symbol(s) not found for architecture x86_64 clang: error: linker command faile
Check if @implementation is absence. This answer gives you more info.
@implementation
Just for reference:
Go to your Project -> General -> Linked Frameworks and Libraries then add WebKit.framework
What you see here is that the WebKit framework is used but the actual binary is not getting linked.