Citizens of all countries require a visa to enter Turkmenistan unless they have special passports. To obtain a tourist visa for Turkmenistan, all foreign citizens must supply an invitation letter issued by a travel agency licensed in Turkmenistan.[1]
Holders of a letter of invitation issued by a company registered in Turkmenistan with a prior approval from the Ministry of Foreign Affairs may obtain a visa on arrival valid for 10 days, and extendable for another 10 days.[2]
Timatic
was invoked but never defined (see the help page).