It seems you are running into the same issue as the original author of this topic, so you should also pass the sizes as ints:
input_size = (10, 1)
hidden_dim = 10
model = nn.LSTM(input_size, hidden_dim, bidirectional=True)
> TypeError: empty(): argument 'size' must be tuple of ints, but found element of type tuple at pos 2

input_size = 10
model = nn.LSTM(input_size, hidden_dim, bidirectional=True) # works