PVP is a game mode of this game, CTF is one type of PVP match
Since there is noone to play PVP in this game, you need 6 people to rig the match.
Make sure you are queueing the same server , which is either EU or US. You may need VPN to have all 6 people in the same server.
For the match, it is some kind of classic Quake 3 CTF match. But to rig a match, each team and teammate take turn to pick up the enemy team's flag and bank it at base. AND take turn means the other team DON'T pick up the other flag at the same time.
You need to rig at least two matches as the win condition is 3. So that the max match score is 3:2 (ie. 5 players got the achievement in one match at most)