[Error] When using plot top losses with custom model

I get the error: heatmap=True requires a model like cnn_learner produces.'

When I try to call

interp.plot_top_losses(9, figsize = (8,6), heatmap = True, largest=top).

I understand this is because I initialized my own custom Learner instead of cnn_learner(I used my own model)

learn = Learner(data, get_cifar_model(), loss_func=nn.CrossEntropyLoss(), metrics=[accuracy])

But when I initialize it with cnn_learner I get the exact error described here:
“Exception: No weight layer”

Is there anyway to get heatmaps from plot_top_losses with a custom model?

Thank you in advance