Pass custom-data through signin_redirect and retrieve it after provider callback

hello every one, CasdoorSDK.signin_redirect({ "custom-data": "data" }); I can pass this to casdoor but how can I get it back after I back from provider (Google) because I need to send it back to backend to process

I find the solution that being stored in the state value in the url, I decoded in the state value

yes, state is the correct solution