uncontrolled_component.js

class ControlledComponent extends React.Component {
  constructor( props) { 
    super(props)
    this.handleSubmit = this.handleSubmit.bind(this) 
  }
  
  handleSubmit(event) { 
    event.preventDefault()
    
    this.props.createAccount(
      name: this.inputName.value,
      email: this.inputEmail,value,
      password: this.inputPassword.value
    )
  }

  render() { 
    return (
      <form onSubmit ={this.handleSubmit}> 
        <input type="text" name="name" ref={(node) => {this.inputName = node} defaultValue="Firstname Lastname" /> 
        <input type="text" name="email" ref={(node) => {this.inputEmail = node} onChange={this.handleChange} defaultValue="[email protected]" />
        <input type="password" name="password" ref={(node) => {this.inputPassword = node} onChange={this.handleChange} />
        <button>Submit</button>
      </form>
    )
  }
}

You missed } in the end of each ref prop.

<input type="text" name="name" ref={(node) => {this.inputName = node}} defaultValue="Firstname Lastname" />