@Irina Thank you for posting your question in Microsoft Q&A, apologize for any inconvenience caused on this.
If you are planning to purchase the toll-free number in US and you are allowed to send or
receive SMS from the below highlighted supported regions. Also, note that all the pricing will be applicable based on the destination region/country for which you are sending the sms.
Refer to this documentation for more information about sms in ACS.
Hope this information helps, let me know if you have any further questions on this.