OpenSearch suggestions route appears to be broken

[brawaru]

According to the description for OpenSearch, https://npmx.dev/api/opensearch/suggestions?q={searchTerms} should be an URL that browsers can use to retrieve search suggestions. However, in testing, trying to retrieve the suggestions from this URL, results in a 404 Not Found HTML page being returned, which should be a 500 Internal Server Error page, according to the message provided - Server Error: Invalid type: Expected string but received undefined.