DAX formula error AddColumn and Summarize

MaxChangeNumberTable =
SUMMARIZE (
CallOff_Delivery_Dates,
CallOff_Delivery_Dates[CallOffID],
"MaxChangeNumber", MAX ( CallOff_Delivery_Dates[ChangeNumber] )
)

=ResultTable=
ADDCOLUMNS (
MaxChangeNumberTable,
"DeliveryDate", LOOKUPVALUE (
CallOff_Delivery_Dates[DeliveryDate],
CallOff_Delivery_Dates[CallOffID], MaxChangeNumberTable[CallOffID],
CallOff_Delivery_Dates[ChangeNumber], MaxChangeNumberTable[MaxChangeNumber]
)
)

Hi everone

My DAX code above is not working. Somehow I couldn't run this code I made in power Query. I don't know where is the mistake.

I want to group according to the CallOffID field in the table I have. Afterwards, CallOffID is repeated in some lines and there is a ChangeNumber corresponding to each CallOffID. These start from 1 and progress upwards. I want to capture the largest number in this ChangeNumber field and list the DeliveryDate next to this number. But it didn't work. I will be glad if you can help.

"Expression.Error: The name 'MaxChangeNumberTable' wasn't recognized. Make sure it's spelled correctly."

It gives this error message