To add a text under button, like this.
We can add a Text Block under Button Block, but in this case, I will use CSS code.
#1. First, find Button Block ID.
#2. Next, use code like this to Custom CSS.
#block-0ea39533e808d86bb773:after {
content: "No credit card · Go live in minutes";
font-size: 18px;
color: #000;
display: block;
text-align:center;
}


