Use postgres functions in ORM, like sequence currval in insert

[jsmolina]

I would like to be able to perform a query like to have the :
INSERT INTO customer (name, customer_id) VALUES ( 'paco', currval('customer_id_seq') + 10)

class CustomerModel(db.Model):
    name = db.Column(db.String)
    customer_id = db.Column(db.Integer, unique=True, index=True)

The idea is to have a secondary colum which is the Primary Key + offset of 10.

Based on documentation, this should work, but it ends inserting a NULL in such value.

await CustomerModel.create(
    name="paco",
    customer_id=db.func.currval("customer_id_seq")
)

Any idea on how to fix it?