Can we create a custom fulfillment status label via API?

[virtualrunners]

Hello all,

looking for some help concerning writing via API into the fulfillment status column. We are working with an external software solution for approving shipments (this has to do with our very specific product). Now we would need to write via our API into the fulfillment status column a new label called approved. Is this possible or are we only allowed to use the labels handled by shopify? e.g. Fulfilled, partly fulfilled etc.

I would really appreciate your help here. Thanks in advance.

Kind regards

Kay