actually I'm working on reactJs project with Laravek API. I want to change the value of a field after choosing a item on a dropdown List. This an exemple : if I choose for example bimothly the value of Contract Rent Per Period Should be 444 (222*2) etc... [1]: https://i.stack.imgur.com/t58vK.png This is my code:

  <Row>
              <Col sm='6' className='mb-1'>
                <Label className='form-label' >Select Period</Label>
                <select className='form-control'>
                  <option>Select Period
                  </option>
                  {periodList.map((item) => {
                    return (<option value='periodicity'>{item.periodicity}</option>
                    )
                  })
                  }
                </select>
                </Col>
                {unit.map((item) =>

                <Col sm='6' className='mb-1'>
                <Label className='form-label'>
                  Contract Rent Per Period
                </Label>
                
               
                  <Input type='text' value={item?.unit_rent_per_month} />
   
           
              </Col>      )}
              <Col sm='6' className='mb-1'>
                <Label className='form-label' for='compl_date'>
                  Date <span className='text-danger'>*</span>
                </Label>
                <Flatpickr
                  className='form-control'
                  value={date}
                  id='date'

                />
              </Col>


                {unit.map((item) =>

                <Col sm='6' className='mb-1'>
                <Label className='form-label'>
                  Contract Rent Per Period
                </Label>
                
               
                  <Input type='text' value={item?.unit_rent_per_month} />
   
           
              </Col>      )}
              
          
            </Row>

I would be very thankful if anyone of you can help mee