AWS::Serverless::Function Won't work with "InlineCode" property

Question

I try to create, using SAM CLI, inline Lambda function code.

I have the following template for my Inline function:

    HealthFunction:
        Type: 'AWS::Serverless::Function'
        Properties:
            PackageType: Zip
            Runtime: nodejs20.x
            Handler: index.handler
            InlineCode: |
                export const handler = (event) => {
                    return { statusCode: 200 };
                }
            Timeout: 30
            Description: 'Health Lambda function'
            Events:
                Api:
                    Type: HttpApi
                    Properties:
                        ApiId: !Ref AwsApiGateway
                        Path: /health
                        Method: GET

And I just run sam local start-api. Then I get an error:

Initializing the lambda functions containers.
Lambda functions containers initialization failed because of expected str, bytes or os.PathLike object, not NoneType
Error: Lambda functions containers initialization failed

It seems like SAM wants CodeUri property (I assume?), but according to documentation: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-resource-function.html#sam-function-inlinecode

It is OK to keep CodeUri empty as long as InlineCode is defined.

So where is the problem here?