unable to understand how X and y are being sent into model.fit

[cerofrais]

Can you please explain what is happening where you are sending in y_tr[:,:-1] into as X into the model.

history=model.fit([x_tr,y_tr[:,:-1]], 
                            y_tr.reshape(y_tr.shape[0],y_tr.shape[1], 1)[:,1:] ,
                            epochs=50,
                           callbacks=[es],
                           batch_size=128, 
                           validation_data=([x_val,y_val[:,:-1]],
                            y_val.reshape(y_val.shape[0],y_val.shape[1], 1)[:,1:]))

[HelloWorldlry]

when I execute this codeing area,I am also facing this issue, if you found the solution could you please help
TypeError: Expected Operation, Variable, or Tensor, got 1（or 0）.