Originally Posted by TIMATIC
Hong Kong (SAR China) - Destination Passport
Passport required.
Document Validity
Passports and other documents accepted for entry must be valid for a minimum of 1 month beyond the period of intended stay.
Hong Kong (SAR China) - Destination Visa
Visa required.
Visa Exemptions
Nationals of Turkiye for a maximum stay of 90 days.
Warning
Visitors not holding return/onward tickets could be refused entry.
Hong Kong (SAR China) - Destination Health
Vaccinations not required.
China - Transit Passport
Passport required.
Document Validity
When in transit, passports and other documents accepted for entry must be valid for a minimum of 3 months from the arrival date.
China - Transit Visa
Visa required.
TWOV (Transit Without Visa)
Passengers with a confirmed onward ticket for a flight to a third country within 24 hours. They can obtain an entry permit on arrival and they must have documents required for the next destination. Passengers with multiple transit stops within China (People's Rep.) must have a total transit time not more than 24 hours.
This TWOV facility does not apply at Fuzhou (FOC), Huangshan (TXN), Mudanjiang (MDG) and Urumqi (URC).
This TWOV facility does not apply to nationals of Afghanistan, Azerbaijan, Iran, Iraq, Kazakhstan, Kyrgyzstan, Malaysia, Oman, Pakistan, Saudi Arabia, Sri Lanka, Syria, Thailand, Turkiye, Turkmenistan and Yemen transiting through Xiamen (XMN).
The Turkish citizen should be able to get a 24h transit visa. You can book PEK-ICN ticket for them (they'll need a K-ETA). If they spend the night in Beijing, they will likely be able to get out of the airport. That's probably the cheapest way to do this. For the 3 days you're in Beijing (check the hours - this matters), have that person fly to Korea for a day or two, and make sure they spend less than 24h in Beijing each way.