If I were you, I'd just get someone from Turkey to buy a SIM card and ship it to you.
I don't think it's that complicated, I don't know how smspva.com gets the numbers, but it's impossible that they buy SIM cards for every client from more than 20 countries. they support Egypt and Morocco.
I asked here because I thought there was a similar service to smspva.com, but unfortunately so far I have not found a similar service or an alternative to them that supports other countries, especially Turkey.
I want to sell digital products and all I want is a Turkish number to communicate with customers in that country instead of a strange country number (people are often more skeptical with unknown country code numbers.)