Assign Reference Field to Order Document with Characters from ID Field

How would I make sure each Order document created is automatically assigned a

reference

field that is basically the last 6 characters of the generated

_id

field, uppercased?My sense told me that I should replace the

client.create(order)

with something like but the issue is that I don't know the

_id

of the just created order, or is there a way to pass it to the patch function?Or perhaps I should just handle the ID generation myself, this way I can perform manipulations on it and provide the

reference

directly in the

create

The point is that I want to avoid making two API calls for dealing with this. Is that possible?

Got myself sorted with nanoid and a custom alphabet