I can’t download twitter on my iPhone 7plus

Hi Sapunna,

in order to download Twitter you'll need to be on at least iOS 14. Since you are using an iPhone 7 Plus the latest version you can upgrade to is iOS 15.7.

Go to Settings > General > Software Update to begin updating.

Good Luck.

Resources:-

Update iphone

Update your iPhone or iPad - Apple Support

As youi appear to be on 13 or earlier Learn how to update your iPhone via recent Macs here:-->

Update your iPhone, iPad or iPod touch with the Finder – Apple Support (UK)

or older Macs and PC here:-->

Update your iPhone, iPad or iPod touch with iTunes – Apple Support (UK)

Update to ios15.7