The club have fallen short since of the promotion places since 2013.
But on Saturday they sealed their place as the north Wales club stayed six points behind leaders Leyton Orient.
Manager Bryan Hughes says the 2-1 win over Barnet keeps their momentum going.
They recovered from letting a lead slip in north London to return home with all three points.
Hughes said: “I’m happy - to guarantee the play-offs was always the first goal after we have done that.
“It’s been too long and that’s the first step. The players deserve credit, because it’s not happened for a few years.
“I really believe in this group. There’s good football players here, and they’ve got a lot of desire.
“Togetherness can take you a long way and now we’ve just got to win as many games as we can between now and the end of the season.”