two way communication between the unity and streamingassets web page for android

Hello, I am developing a project for android where, there will be a unity scene and a web page. Changing the value in the webpage will change the scene and vice varsa.

I am using android webview and showing a web page from local asset folder. Now I need two way communication between the unity and web page. Thats why I need to communicate with webpage java script with unity script. Butting ewb javascript in StreamingAssets folder create compiling error.

How can I solve this problem. Please help me. Thanks In advance