Calendar next is not working

[Woolim Lee]

I try create next button in tui calendar and material-ui-core.
but I applied handleClickNextButton, It shows me TypeError: Cannot read property 'getInstance' of undefined

here's my calendar code.

...

  calendarRef = () => React.createRef();

 handleClickNextButton = () => {
    const calendarInstance = this.calendarRef.current.getInstance();

    calendarInstance.next();
  };

...

render(){
return(
 <Button className={classes.changeBtn} onClick={this.handleClickNextButton}>
  <ChevronRightIcon />
 </Button>


 <Calendar
  week={timeLimit}
  month={monthConfig}
  view="month"
  theme={themeConfig}
  taskView={false}
  usageStatistics={false}
  isReadOnly={true}
  schedules={care.flat(1)}
  calendarRef={React.createRef()}
 />
)
}