Looks like I've answered my own question here: Upon inspecting what link comes out the other side where the image should be, I discovered the ampersands were getting replaced. Using URLEncode() on the whole link doesn't work, but I discovered I can just build a location string from address, street, town, and state, or from lat and long, and URLEncode() that. Then, I add the base URL as plain text to the URL box, with the expression inserted after "&location=".
![JCGuarneri_0-1654791618638.png JCGuarneri_0-1654791618638.png](https://community.esri.com/t5/image/serverpage/image-id/43119iE23A26014D4480FA/image-size/medium?v=v2&px=400)