I found the HK mobile numbers prefix 9291**** is not yet supported in this library.
According to below phone numbering plan announced by Office of Communication Authority of HK (SAR), China,
the numbers 92910000~92919999 have been assigned.
https://www.ofca.gov.hk/filemanager/ofca/en/content_311/no_plan.pdf
I found the HK mobile numbers prefix 9291**** is not yet supported in this library. According to below phone numbering plan announced by Office of Communication Authority of HK (SAR), China, the numbers 92910000~92919999 have been assigned. https://www.ofca.gov.hk/filemanager/ofca/en/content_311/no_plan.pdf