Incorrect Text Domain

Hi Developer,

This plugin slug is user-submitted-posts, but your Text Domain is usp. Change your Text Domain so it is equal to your slug and modify the text domain in all your source files. This change is needed because your “Requires at least” is below 4.6. (see https://developer.ww.wp.xz.cn/plugins/internationalization/how-to-internationalize-your-plugin/#text-domains)

This implementation will be better for plugin localization.