How to add text below fields at checkout page?

Store Design
1

Hi, How can I add the text below fields at checkout page like this site,

It may be the toolkit text, but I have no idea how to make it appear under the field box

Shopify Checkout.png
Shopify Checkout.png594×580 8.35 KB

Thank you.

2

Thanks, @devangfour but this is not a tipping option. I just want to add text below the email and phone number field

3

@VuongTuanAnh I guess they use custom checkout.liquid (available for Plus stores only)