If you want to play through the hunts in Monster Hunter Now at 60 frames per second, then you can check out this guide at Seeking Tech to see how you can properly set it up.
1. To start off, make sure you tab your profile picture located at the bottom left side in the main menu.
2. In the next screen, you can then head into Settings.
3. You should find the 60 fps While Hunting option in the Settings menu.
4. When you select it, you should see a message appear saying that 60 fps will result in more processing load on your smartphone or tablet. This may cause the battery to drain faster than normal. If your device is not powerful enough, then the frame rate may not hit 60.
Here, you need to select OK to continue.
You should now be able to battle at 60 fps in Monster Hunter Now as long as your device is powerful enough to handle the extra frames.