Invoice Update Issue

Hello,

I am trying to update invoice no. update, but i am getting error "Adding invoice allowed only for sellers with invoice configurations MANUAL or
BLKUP" , we are using vendor_self shipping method. Please look over that it's very urgent.

My Request & Response:

curl -X POST --header 'Content-Type: application/json' --header 'Accept: application/json' --header
'X-Auth-Token: 676655ba-269b-337b-975b-9b5eeb0e2575' --header 'X-Seller-Authz-Token: fc99b70e-40d9-41ce-be91-01f944d5451b'
--header 'ClientId: S16576' -d '{"invoiceUpdates":{"SLP1081604686":{"fulfillmentType":"VENDOR_SELF"
,"invoiceCode":"DelexINV#5635"}}}' https://apigateway.snapdeal.com//seller-api/orders/invoice

response:
{"metadata"
:{"requestId":"5e1008aa-49b3-4eb9-a988-2bd16d91ff50","clientId":"S16576","responseTime":13,"requestedURI"
:"POST /orders/invoice"},"payload":{"invoiceUpdatesResponse":{"SLP1081604686":{"operationSuccessful"
:false,"errorMessage":"Adding invoice allowed only for sellers with invoice configurations MANUAL or
BLKUP"}}}}

Thanks,
Apurba