Depending on the nationality of the passport holder, the single-entry or multiple-entry Turkey online e-visa enables stays of 30 or 90 days. It was introduced in 2013.
To enter Turkey, eligible citizens must submit the online Turkey e-Visa application form.
This can be completed quickly it removes the need to travel an embassy or consulate.
From the date of issuance, the Turkey e-Visa is normally valid for 180 days.
https://www.evisaprime.com/country/turkey