include gpt model to comment my code or data

Question

Found on youtube that you can import openai language models in your code so i tried it. As far as i can see it needs payment to use.

import openai

# Define your code snippet
code = """
def add(a, b):
    # This function adds two numbers
    return a + b
"""

# Use the GPT model to generate comments
response = openai.Completion.create(
    engine="text-davinci-002",
    prompt=f"Please comment on the following code:\n{code}",
    max_tokens=50,  # Adjust as needed
)

# Extract the generated comments
comments = response.choices[0].text

# Insert comments into your code
code_with_comments = code + "\n" + comments

# Print or save the updated code
print(code_with_comments)

Is there any other model that is for free and can be added to my code in order to comment results?