How to add contextual information with Flask plugin?

Elastic Observability APM
5

Here is a little snippet combining Elastic APM in a flask app and adding some custom context:

import elasticapm
from flask import Flask
from elasticapm.contrib.flask import ElasticAPM

app = Flask(__name__)

app.config['ELASTIC_APM'] = {
    'DEBUG': True,
    'SERVER_URL': 'http://localhost:8200',
    'SERVICE_NAME': 'test-service',
}
apm = ElasticAPM(app)


@app.route('/')
def index():
    elasticapm.set_custom_context({'my-context': 123})
    return 'OK'

Please let me know what you are missing from this.