If you're having trouble uploading photos/videos from your device to Shopee App, it is likely because you have not granted permission to Shopee App to access photos on your device. To grant Shopee App access to photos on your device:
For Android users
Go to your device’s App settings > Select Shopee App > Permissions > Select Files and media > Allow management of all files.
For iOS users
Go to your device’s App settings > Select Shopee App > Enable toggle for Camera.
Once you’ve done so, open the Shopee App and try uploading again.