LiveChat DB Schema

i am building a live chat application in Laravel. i have the following models: UserModel TeamModel TeamMemberModel BotModel ConversationModel ConversationMessageModel -> agent_id, agent_type

ConversationMessageModel has agent_type which is either bot or human, then the agent_id. the problem with this is i cannot get all messages together with the corresponding agent. Please help solve the problem, i am open for schema redesign