Everyone was sworn to secrecy and told that the meeting in Khartoum would never take place. For months, however, secret negotiations took place to plan it. Emissaries flew by helicopter to remote corners of the CAR to draw up outlines. Other meetings were held in Sudan.
https://www.theafricareport.com/190856/russia-yevgeny-prigozhin-vladimir-putins-africa-machine/