If you mean the name under the app/widget, Apple doesn't allow that. Here's what the developer told me.
"So far what I've seen is they put an unprintable character for the app name, which means there is no app name beneath the app icon on the home screen or any widgets. But it is super confusing because when you go to add the widget in the gallery, the widget can only be found down at the bottom of the app list with no name. This would confuse way more people than the number of people who want the widget name removed.
I've also heard in the past that they have trouble getting the app through App Review every time and keep submitting until they finally get a reviewer that doesn't notice that the app doesn't have a proper display name."
Thanks I have a few that do it and it confused me bc when i saw the widget setup there’s a tick for widget name hide