I am trying to integrate bitmovin player with custom reciver web app but i could not control the player once casted. How to remotely control the player using the sender?
If you have the Bitmovin Player set up in your sender app, you need to enable casting support using config.remotecontrol configuration. Please set type: 'googlecast', receiverApplicationId: 'your-custom-receiver-app-id', and you will likely need to set the receiver version to v3 (aka Google Cast Application Framework (CAF)) using receiverVersion: 'v3' (v2 is deprecated by Google for new apps).
For the cast receiver, I'd recommend starting with Bitmovin's sample receiver app as it contains code to handle more advanced use cases (like DRM support). Build the project and publish a cast application pointing to it should be all you need (make sure to use this app ID in the sender app's player configuration as mentioned in the previous paragraph).