Why does the received message not show the number but only the sender's name?

Such messages are generally pushed by merchant clients and are not sent from operational numbers. If you don’t wish to receive messages from the respective merchant, you can go to [Messages] >> tap a message >> tap the three dots in the upper right corner >> [Block & report spam]. Besides, to avoid receiving such messages, you can also go to [Messages] >> [Profile] >> [Messages settings] >> [Spam protection] >> turn on [Enable spam protection] to help detect spam.