how to connect sms provider to my crm 2016

i have sms provider.

i want to connect it to crm 2016.

i want to send sms message to users of my organization when one entity assign to user. 

This should be defined as workflow on any entity that i want, when assigned entity to other user.

Please tell me step by step what i must doing.

Is there any solution which I will import it into Crm 2016.

Thank you for explaining in detail :)