What might be wrong with my drivetrain?

Hey all! Hope you doing good!

I’m fairly new with fixies, this is my second proper fixie and I just bought it a few weeks ago. Well the weather is warming up over here so I started using it more lately but the noise is extremely annoying and loud.

I’m not sure where the problem is though and I’m hoping that from the video you guys may have an idea of what it is. I’m not sure if it’s the crankset, the rear cog or maybe the chain. I can tell with absolute certainty that my drivetrain components overall are shite and cheap.

I have no money to spend on a new crankset right now which can go up to 200 euro easily if I’m buying a good one.

Any ideas and insights appreciated, thank you in advance!