I’ve deleted some unnecessary parts of your model and just checked, if Mask.weight are in the parameters, and it seems to work.
Also, I’ve formatted the code in your post. You can post code enclosed in three `.
class Mask(nn.Module):
    def __init__(self):
        super(Mask, self).__init__()
        self.weight = torch.nn.Parameter(data=torch.Tensor(1, 1, 1, 1), requires_grad=True)
        
        self.weight.data.uniform_(-1, 1)
        
    
    def forward(self, x):
        masked_wt = self.weight.mul(1)
        return masked_wt


class Model(nn.Module):
    def __init__(self):
        super(Model, self).__init__()
        self.Mask = Mask()

    def forward(self,x):
        x = Mask(x)
        return x

model = Model()

for name, param in model.named_parameters():
    print(name, param)