Thanks for the reply.
I’ve tried it:
X = np.asarray(xtrain_pad).astype(np.float32)
Y = np.asarray(train_label_seq).astype(np.float32)

num_epochs = 10
history = model.fit(X, Y, epochs=num_epochs,
                    validation_data=(xtest_pad, test_label_seq), verbose=2)

But now I get the following error:
Traceback (most recent call last):
  File "c:\Users\vit\code\qism-ticket-classification\tensorflow\multi-class.py", line 100, in <module>
    Y = np.asarray(train_label_seq).astype(np.float32)
ValueError: setting an array element with a sequence.

I hope someone can help me there