getting "Saving failed" error at mobile app

I am getting below mentioned issue at the mobile application.
what could be the reason ?

<img width="720" height="1608" alt="Image" src="https://github.com/user-attachments/assets/a3643293-fbbd-4a45-80da-40c64168af27" />

i have self-hosted the mergin-maps application on my server,