whatsapp chat backup is not worikng

my WhatsApp chat was last backup completed on 23-12-2022 2:52pm IST.

I kept the auto backup option in daily mode. but it is not backup on daily basis.

on 27-12-2022 I checked about chat backup and observed that it is not backup in daily mode, even I try to do in manual mode it is stuck in preparing and not uploading.

I need solution for this issue, and I doubt that is it only my WhatsApp problem or iOS WhatsApp issue.