We are from the hairdressing salon. How to send text messages to customers is more appropriate?

Hairdressing shops should take the initiative to send text messages to customers at ordinary times to complete these two steps:

Nowadays, membership management system can generally export excel tables of customers' mobile phone numbers. If you don't have a mobile phone number, you can add it to the following interface, including local+foreign.

Import these figures into the above interface and record the activities of the hair salon. When everything is ready, send it in 3 seconds.