Carbon::createFromFormat 'A two digit day could not be found'

I am integrating with Zoho CRM Insert Contacts,

I keep getting an error about date format in php. It keeps giving me an error and message 'A two digit day could not be found Data missing'

Here is my Php Code:

$record->setFieldValue("DATE_OF_BIRTH_1", \Carbon\Carbon::createFromFormat('dd/mm/yyyy', $clientData['birthdate']) ->format('Y-m-d')

I am using ant'd datepicker with format like this:

<DatePicker 
onChange={(_, dateString) => setValue('birthdate', dateString)}
format="DD/MM/YYYY"
/>

As I submit, I get an error as mentioned above: