How can I add a couple of lines of explanatory text in between the fields in a form block?

About: Squarespace Circle Leader since 2017. I value honesty, transparency, diversity and great design ♥.
Work: Squarespace Developer and founder of SF Digital, building the features Squarespace didn't include™. 
Content: Links in my posts may refer to SF Digital products or may be affiliate links.

Catch up on all the release notes and announcements 2023 [for Circle members only]. There's a public version here too!
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