The Way of the Open Hand monk gets the Open Hand Technique feature at 3rd level, which allows the following effect as one of the options when using Flurry of Blows:
Whenever you hit a creature with one of the attacks granted by your Flurry of Blows, you can impose one of the following effects on that target:
[...]
- It must make a Strength saving throw. If it fails, you can push it up to 15 feet away from you.
Is the distance I can push a creature using the Open Hand Monk's Flurry of Blows feature reduced if I push the target through difficult terrain?