The phrase "to require additional support" means to need or demand more help, resources, or assistance beyond what is normally provided. Full definition
I have added a sheet with hints and tips for students who require additional support. (tes.com)
If a student requires additional support to reach their targets, this will be provided by their teacher in the form of differentiated work, or sometime on additional teaching sessions. (uckfield.college)
All families can become aware that it's reasonable and in fact, necessary at times to require additional support for a student. (confidentparentsconfidentkids.org)