Request i am making to upload the file

!curl "https://content.zohoapis.com/crm/v6/upload" -X POST -H "Authorization: Zoho-oauthtoken 1000.xxxx" -H "X-CRM-ORG: xxxx" -H "feature: bulk-write" -F "file=@sample2.csv.zip"

Response: 

{"x-error":"Check if headers [feature, X-CRM-ORG] are present and valid","info":"Forbidden"}

How can i resolve this