How to declare the weight and bias values for a convolution layer?

Greetings,

I want to add a convolution layer in the existing squeezenet network. However the errors shown like this:

Error using assembleNetwork (line 47)

Invalid network.

Error in trainyolov3 (line 80)

newbaseNetwork = assembleNetwork(lgraph); % for tiny-yolov3-coco

Caused by:

Layer 'add_conv': Empty Weights property. Specify a nonempty value for the Weights property.

Layer 'add_conv': Empty Bias property. Specify a nonempty value for the Bias property.

Therefore, I want to ask on how to declare the weights and bias value for that layer? My code is as shown below:

lgraph = disconnectLayers(lgraph,'fire8-concat','fire9-squeeze1x1');
layer = [
    maxPooling2dLayer([3 3],"Name","pool6","Padding","same","Stride",[2 2])
    convolution2dLayer([1 1],512,"Name","add_conv","Padding",[1 1 1 1],"Stride",[2 2])
    reluLayer("Name","relu_add_conv")];
lgraph = addLayers(lgraph, layer);
lgraph = connectLayers(lgraph,'fire8-concat','pool6');
lgraph = connectLayers(lgraph,'relu_add_conv','fire9-squeeze1x1');
newbaseNetwork = assembleNetwork(lgraph);