Please note that Questions about how to pass Trailhead challenges are not on topic, because these challenges are intended to be independent demonstrations of your abilities.
Trailhead Help (https://trailhead.salesforce.com/en/help?support=home)can provide assistance for situations where Trailhead does not appear to be functioning correctly. You can reach out to them if this is the case.
Have you created the metadata? After looking at the error message it looks like you haven't created metadata yet or maybe you have misspelled the custom metadata.
Trailhead Help (https://trailhead.salesforce.com/en/help?support=home)can provide assistance for situations where Trailhead does not appear to be functioning correctly. You can reach out to them if this is the case.
Thanks!
Have you created the metadata? After looking at the error message it looks like you haven't created metadata yet or maybe you have misspelled the custom metadata.
Thanks
Gulshan Raj