Why transformer hidden layer use softmax as activation function

[WJC]

Softmax layer Clarification - Deep Learning Specialization / DLS Course 2 - DeepLearning.AI
In the above topic, we said that softmax is used in the output layer, not the hidden layer.

However, In the transformer, multihead attention is a hidden layer, and in multihead attention, QK^T passes through a softmax function… Why?

[jonaslalin]

Because attention is a weighted average and the attention weights should therefore sum to one. Softmax ensures that.