Issue description

The question 6 in "Quiz: Managing and Customizing API Gateways" the metric name it's "custom_metrics", not custom-metrics as writed in option A, C and D.

Workaround:
update the guide text to ensure consistency. change all instances of 'custom-metrics' in options A, C and D to 'custom_metrics'. this correction will align with the metric name used in question 6 and prevent any potential confusion for students during their learning process.