The Turkish government doesn't seem to have any official sites for this, but other countries have government agencies that report it as such (as of Apr 18, 2022)
US State Dept - Turkish Embassy
Passengers, regardless of their nationality, over the age of 18 who have not been vaccinated or with no record of Covid-19 (recovery) are required to submit PCR tests with a negative result, performed at most 48 hours before their domestic flight, as of September 6, 2021. PCR tests are not required in domestic flights for those who are vaccinated and flight is at least 14 days after the second dose or for those who are in the immunity period after a Covid19 infection.
In an attempt to limit the spread of COVID-19, most governments have implemented preventative measures and restrictions.
These could include:
- curfews, movement restrictions, or lockdowns
- the obligation to wear a face-covering, a surgical or respirator mask in some circumstances
- the obligation to present proof of vaccination or a COVID-19 test result to access public and private services and spaces, including transportation, restaurants and cultural sites
Foreign authorities might not recognize or accept proof of vaccination issued by Canadian provinces and territories. You may need to obtain a translation, a notarization, an authentication, or the legalization of the document.
I have not found another major country governmental website that disagrees with either of these previous ones.
The answer seems to be that, yes, you will be required to have official vaccination papers OR a negative PCR test. These regulations are subject to change.