sampling is not working

[flit86]

i"m new in DL .I'm trying to write the same assignment but with new document. and sampling is not working.
Traceback (most recent call last):
File "C:/Users/shevc/Dino.py", line 109, in
indices= sample(parameters, char_to_ix, 0)
gradients["dWaa"][1][2] = 10.0
File "C:/Users/shevc/Dino.py", line 59, in sample
gradients["db"][4] = [10.]
Waa, Wax, Wya, by, b = parameters['Waa'], parameters['Wax'], parameters['Wya'], parameters['by'], parameters['b']
gradients["dby"][1] = [8.45833407]
KeyError: 'Waa'

can you help me?