How can I contact the developer of an app that crashes on iPhone 15?

When using an app (that doesn't currently have an update available) on iPhone 15 (that is completely up to date with software) the app crashes at the same exact spot every time. Now I left a review in App Store but I want to contact the developer and ask them to fix the glitch with their app but when I click on "developer website" the page isn't valid. So what do I do?

[Re-Titled by Moderator]

Original Title: App support