Sorry, if I introduce even more misunderstanding 
If you want to add outputs of two layers (meaning to sum them up), you can use tf.keras.layers.Add  |  TensorFlow Core v2.7.0
The tricky thing here is that it should be used on tensors of the same shape. But Embedding will output 2D tensor and Dense usually outputs 1D tensor. So you have to either reshape Dense output or use average pooling / mean pooling on Embedding output before adding them together.
Alternatively, you can concatenate two tensors with tf.keras.layers.concatenate  |  TensorFlow Core v2.7.0
Here you’ll face the same problem with different shapes and have to make them compatible.