The Fortbyte number 51 is in Neo Tilted, but be careful there is a trick: you will first need to equip yourself with the Cluck Strut emote which is obtained at level 31 of the battle pass (paid version).
Then find the banana stand, a small yellow building in Neo Tilted, located at the western entrance of the city. A zebra crossing is located just in front of the stand, cross it with the emote (which allows you to move around) to unlock the Fortbyte. It will appear in the middle of the zebra crossing.
Written by Augustin "TheGreatReview" Héliot. Translated from French by Millenium.us.org.