How to add text under a product name?

Store Design
1

Hi,

I want to mention a text like below the product item name, reference mentioned below. Kindly help, URGENT!

2

@darkside_d
Kindly Share your Store Url So i can help you.

3

@Zworthkey

www.dumbledog.com

URL provided above.

I have basic knowledge of coding, kindly help in resolving it. Im not looking for hiring, just need guidance to proceed the steps required. thank you