how to update dynamodb with pynamodb ORM?

I'm creating a user table in dynamo db and want to utilize pynamodb ORM, sample class below.

pynamodb class

from pynamodb.models import Model
from pynamodb.attributes import UnicodeAttribute

class UserModel(Model):
    class Meta:
        table_name = "user"
    first_name = UnicodeAttribute(range_key=True)
    last_name = UnicodeAttribute(hash_key=True)
    email = UnicodeAttribute(null=True)

I also have a pydantic class for data validation , see below. which validates the data, when client posts data to my REST API. Now i need to update my dynamo db table , to add another attribute , say age. I understand dynamodb doesn't really have a schema, per say. so we can add/update any attributes in the table, but when we use pynamodb ORM, do i just update the UserModel class above? add another attribute age to my UserModel class and also to my pydantic class. is there anything i need to update?

from datetime import date
from uuid import UUID, uuid4
from enum import Enum
from pydantic import BaseModel, EmailStr


class User(BaseModel):
    first_name : str
    last_name : str
    email: str

I want to update

Update your UserModel class with a new attribute and then reflect the change to your pydantic class.

from pynamodb.models import Model
from pynamodb.attributes import UnicodeAttribute, NumberAttribute

class UserModel(Model):
    class Meta:
        table_name = "user"
    first_name = UnicodeAttribute(range_key=True)
    last_name = UnicodeAttribute(hash_key=True)
    email = UnicodeAttribute(null=True)
    age = NumberAttribute(null=True)  # New attribute


from pydantic import BaseModel, EmailStr
from typing import Optional

class User(BaseModel):
    first_name: str
    last_name: str
    email: Optional[EmailStr] = None
    age: Optional[int] = None  # New attribute

Consider backfilling your existing data