JAVASCRIPT

on ddrop function react dropzone parameters

 const onDrop = async (index, acceptedFiles) => {
   .
   .
   .
 }
 
  <Dropzone onDrop={acceptedFiles =>onDrop(1,acceptedFiles )} accept=".pdf" maxSize={50000000}>

on ddrop function react dropzone parameters

onDrop(accepted, rejected, myArgument) {
  console.log(accepted, rejected, myArgument)
}

<Dropzone onDrop={(accepted, rejected) => {this.onDrop(accepted, rejected, 'third')}}>
  <p>Drop files here...</p>
</Dropzone>