Certificate field should be optional in digital purchase

[vbabuEM]

Reported by Sreekanth MR
Calling status returns the following error
{"errors":[{"message":"Cannot query field \"certificate\" on type \"OrderCustomFields\".","locations":[{"line":75,"column":13}],"extensions":{"http":{"status":400,"headers":{}},"code":"GRAPHQL_VALIDATION_FAILED"}}]}

Requirement:
Fix the error.
The certificate field should be optional and not mandatory.