Facing Issue in Installing Custom APP

I have previously created some custom apps in the Freshservice product.
But now, while installing my new app in my trial and paid account, I get this error

There was an error during installation. If this issue persists, please contact support.
The error should be a JSON Object with a message or a status parameter.

However, when I run the code in development, I can install and use the App, and when I also simulate the OnAppInstall function, it works fine. But when I convert it into a custom app and try to install it, I face that error. During installation, I have asked for three parameters. I didn’t face this issue with the past apps I developed.

Could anyone help me with this in the earliest?