Hi @1_DipikaD 
Try few things:

1. Try using == 1 instead of === '1' and check for an alert.

2. Check the correct value of the dropdown choice list.

3. check if "request_type" field is visible on the form, try using alert first and then show field message.

If my response helped please mark it correct and close the thread so that it benefits future readers.

Thanks,
Brahmjeet