Can’t get Twitter app on iPhone 7

I am trying to download the Twitter app on my iPhone 7 (OS 12.3.1) and the download button is greyed out so I can’t download it.

Had the app loaded before and it started disappearing. Deleting the app & reloading it worked for a short while, then this issue started.

i have enough available memory on my phone and a credit card on file so those are not issues re: this.

Any info/assistance greatly appreciated!