Dear @paul2009,
Thank you for responding!!
Ah, yes, our main donations run through Network4Good. Sorry. I can see now how my questions was misleading.
The adoptions run via Squarespace.
This is my test page... https://www.reteti.org/kapai
Once you click the adopt button, in the contribution box, there's "other amount". I'm also attaching a screenshot of what it looks like when I edit the Donation Button.
I can't seem to find any Squarespace documentation on this.
Have you seen this before?