Well, it looks like you figured out the #[5] API and removed the quotes around the url. What took so much thought when it came to image hosting? Also, what are you using to create the Nostr events?
Discussion
At first I couldn’t figure out programmatically uploading to nostrbuild so I gave up on that. Then was gonna use AWS S3 which worked and also tried my own flask app for hosting images. I being a noob with Nostr thought that relays cache images. So I thought if I just temporarily host an image for a day I’m good, but that’s not how it works. I finally found out Nostr.build has an API and now we are good. I use python with the Nostr package here’s a basic setup I published. https://gist.github.com/Jxck-S/b6ffe6cc30e4139c3205f2e0b7575cad