Parameter q is invalid

Summary:

We are trying to query a quote using a newly created text attribute draft_Order_ID_c but has this error response. What might be the issue?

Content (please ensure you mask any confidential information):

"Parameter q is invalid.\nInvalid token draft_Order_ID_c at the following path draft_Order_ID_c.\nField draft_Order_ID_c is not searchable or sort-able for current user."}

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):

/rest/v14/commerceDocumentsOraclecpqoTransaction?q={draft_Order_ID_c: 'ABCD'}