You need an embassy visa for Turkmenistan if you have a Hong Kong SAR passport

Travellers need a visa to visit Turkmenistan for Business or Tourism. A paper or embassy visa is the only visa available for travellers visiting Turkmenistan. The visa is typically a stamp or sticker added to the passport. Travellers must obtain this visa from a local embassy, consulate or visa center before travelling. Travellers can get a visa on arrival at the airport in Turkmenistan if they receive an invitation from the State Migration Service of Turkmenistan. However, travellers without a visa may encounter issues during check-in. The government of Turkmenistan recommends that travellers secure a visa from an embassy of Turkmenistan before travelling.