从单个表单中获取数据并在环回中保存多个模型

I am trying to take data from a single form that has the user credentials along with user details and store them in seperate models in loopback. I have created the required models and relations but I am confused on how to do this. Does this happen automatically since the relations are specified or do i have to make use of the afterRemote method to do so ? I am trying to take data from a single form tha