How can I subscribe on my Talkatone app but the subscription is declined

Please make sure your iOS is upgraded as high as it can go. On your iPhone, select Settings > General > Software Update. That will show your version iOS and if you are eligible for an update, you will be prompted to do so. My concern is that your older iPhone cannot be updated to the iOS that Talkatone requires. You can ask them directly:

For product support inquiries, please click here or email support@talkatone.***

[Email Edited by Moderator]

My concern is that your older iPhone cannot be updated to the iOS that Talkatone requires.

Talkatone app -> compatibility iPhone -> requires iOS 12.0 or later.

OP has iPhone 6s Plus with iOS 15