Upsert Not working with the class clusters in queries

Hello ,

I added one class Customer with the two properties name and customerNo
And added the cluster for the class using below query

ALTER CLASS customer ADDCLUSTER UK_Customers

Also given the Unique index name in the customer vertex

As per the docs
https://orientdb.com/docs/last/sql/SQL-Update.html
added the upsert Query for adding and updating the customers by using the below query

UPDATE customer CLUSTER:UK_Customers SET name = “David”, customerNo =“C001”
UPSERT RETURN AFTER @rid, * WHERE customerNo =“C001”

but getting this error

Is there any workaround for UPSERT for the queries using cluster names Or is there any syntax error in above update query with UPSERT keyword