I have in my project configured the URL callbacks and none of them work, neither the local URL nor the production one works, always when I click on login I get invalid callback url but I have them in the callbacks of my NEXTJS app.
It seems that when you click “Add callback to application now” from the Kinde screen “Invalid callback URL” it does not recognize the app you have because the form does not show its data.
It's weird because I tried to add it myself by going into the dashboard in the app settings, I saved it and it still gives me the error “invalid callback url” but in production it works and the production domain is also in the allowed domains.
I changed by mistake the client id and the client key and put those of my M2M app and I didn't even realize it and that's why I didn't get the app info and when I added the allowed callback url it didn't work, looking at the url parameters of the login screen I realized that I was using another client id.