Save_ Format = "tf" is invalid

When I tried to save the model, it gave an error prompt ‘Saving the model to HDF5 format requires the model to be a Functional model or a Sequential model. It does not work for subclassed models, because such models are defined via the body of a Python method, which isn’t safely serializable. Consider saving to the Tensorflow SavedModel format (by setting save_format=“tf”) or using save_weights.’. The layers of my model were all written and customized by myself, but I also saved them in TF format according to the requirements, but it still reported an error. How do I solve this

In order to expedite the trouble-shooting process, please provide a stand alone code to reproduce the issue reported here. Thank you.

Thank you very much for your reply. This is the GitHub link of my code: