'Pygame Module' not working

[37_VA_VEER CHAKRABORTY]

Hi,
I am a beginner in Python and I have started with the 'Pygame' module. I
was making a 'Flappy Bird' game with the module with the help of Youtube
videos. I was able to create a blank window. I had downloaded the game
assets in my computer in a folder called 'Python' and in a subfolder called
'assets'. I tried to upload the Flappy Bird picture and other sprites with
the code -
pygame.image.load('assets/Flappy Bird.png')
However, when I ran the script it was showing an error message - File not
found
Please advise me on how to upload the sprites and where I was going wrong.
Thank You,
Regards