How to create the input for GCN

[Samiendu]

Hi, I am stuck with a problem. Before sharing the problem I would like to let you know that I am not from CS background therefore I expect answers in simple terms.
I have a 2D rectangle. I have meshed it with triangles and I have the nodes now. I have the patches too.
Now I know that input to the GCN is in this format:
data = Data(x=x, edge index ,y)
where edge index is the COO (2*n_ matrix) format.
My question is whether we should add self loop in the adjacency matrix if we try to generate the COO format from the adjacency matrix.
Then we will have:
{0->0}
{1->1}
.
.
.
etc

My question is