Clarification on Financial Sponsor Letters for Student Visa Application

am currently in the UK on a Post-Study Work (PSW) visa and am preparing to switch to a student visa for my PhD at the University of Huddersfield. My situation is as follows:
• I am on a university scholarship that only covers my tuition fees.
• I am funding my living/maintenance costs myself.
• I have been in the UK for more than 12 months.
In the student visa application, there are two sections requesting:
1. “A letter from your current or past official financial sponsor confirming you have their permission to continue your studies in the UK”
2. “Letter to prove official financial sponsorship”
I would like to confirm whether, in my case, I am allowed to leave these sections blank, since I am covering my living costs myself and my CAS already confirms tuition coverage.
Could you please advise if any additional letters or documentation from the university or my scholarship provider are required for these sections when switching from PSW to a student visa?