Not required for some (predominantly European) nationalities; most other nationalities can obtain a 90-day visa electronically at https://www.evisa.gov.tr/en/.
Your passport must have at least six months' validity remaining, or you may not be admitted into Turkey. See the website of the Ministry of Foreign Affairs (http://www.mfa.gov.tr/default.en.mfa#) for the latest information.
The invitation letter will be issued after the successful registration.
Your name must be listed exactly as it appears on your passport. Any differences between the name on your passport and the name on your invitation letter or other documentation could lead to a delay and/or denial of your visa.
Please note ICPSE 2023 Conference and the organizing committees of the conference are not authorized to assist with the VISA process beyond providing the Notification of Invitation Letter issued by ICPSE Conference and Conference Committee Board. Should your application be denied, ICPSE Conference and the organizing committees of the conference cannot change the decision of the Ministry of Foreign Affairs, nor will ICPSE Conference and the organizing committees of the conference engage in discussion or correspondence with the MOFA or the Embassy on behalf of the applicant. The registration fee cannot be refunded when the VISA application of individual being denied.
It takes around one month for the Embassy to process the VISA application, please register as early as you can to make sure you have enough time. For most attendees, it is easier to apply for a Tourist ("L") visa; an invitation letter is NOT required for obtaining a Tourist visa.