Create unit with profile fields info by using javascript sdk

Hello rual,
Ok i understood you,
so kindly can you guide me to the method of update unit? is it

sess.updateItem()

or where can i search for that?
i have tried several ways
i have tested with returned obj
as :
obj.updateCustomProperty
i have received code=0 but the prop value doesn't saved in profile field of the unit

thanks

This is my simple code to create a unit with profile fields

sess.createUnit(sess.getCurrUser(), infoArr[0], this.state.selectedHWID, flags, function (code, obj) {
            console.log('reposne code is  : ')
            console.log(code)
            if (code === 0) {
                console.log(obj)
              
                obj.updateProfileField({itemId: obj._id ,n:"year",v:"2020"}, function(code,col){

                    console.log(' returned code' +code)
                    console.log(col)
                })
               
              
            }
            

        })

But i have got
{"error":4, "reason":"VALIDATE_PARAMS_ERROR: {itemId: long, n: text, v: text}"}

in network request console

i already have loaded "itemProfileFields"

i tried to do :

sess.getIIem(returnObj._id).updateProfileField..

but the item returned is null but i don't know why

so kindly can you explain me the correct procedure to reach updateProfileField method, is it by getITem or by returnObj.updateProfileField?

thanks