You don't have to choose between the TOEFL iBT test and the TOEFL Essentials test — you can accept both! And doing so will give you the broadest range of qualified international applicants of any test provider.
If your institution already has a 4-digit score-user code for TOEFL tests, you and your applicants will use that same code for TOEFL Essentials scores. If you don't have a TOEFL score-user code, apply for one.
If your institution uses a data management system for test scores, it will need to be configured to accept TOEFL Essentials scores, as with any new test. View Score Reporting for guidance about updating your data system.