Full Ride London

 Any idea how to get this route uploaded in Zwift ?

I desperately need it before the race please.

https://www.strava.com/activities/72134459?hl=en-GB

Any App which can do the job ? like TrainerRoad ?

Ride London pretzel, keep on until 100km. Enjoy.

No way to create custom courses on Zwift

You can convert the GPX file to a workout if you “Need” to simulate the route using https://whatsonzwift.com/gpx-to-zwift-workout/