The Gunslinger and the Heiress

This is an Apple Books audiobook narrated by a digital voice based on a human narrator.
From two different worlds 

Years ago, heiress Hannah Lansing was forced to give up the man she loved. Now, to save the family business, her grandfather demands she marry someone she feels nothing for. Torn between duty and desire, there's only one man Hannah can turn to… 

Gunslinger Caleb Houston is shocked when Hannah arrives in San Diego—he never expected to see her again! In the eyes of society, they're worlds apart, but can Caleb finally convince Hannah to put her own happiness first and trust in the power of the love they share? 

"Fans of western and marriage-of-convenience romances have it all." —RT Book Reviews on Texas Wedding for Their Baby's Sake