This is a very common situation, you are not alone 🙂
Yes, possible pa rin mag-apply ng student visa kahit hindi aligned ang kukunin mong course sa degree at previous work mo. Hindi naman required ng Australia na same field ang aaralin mo, ang mahalaga (which is the tough part I think) is dapat kaya mong i-explain nang maayos kng bakit logical ang shift mo. In your case, kahit Bachelor in Physical Education ang tinapos mo, may almost 5 years ka nang solid work experience as a WFM Specialist sa BPO, which already involves planning, analytics, operations, at people management, so hindi siya random career move. Instead of forcing an IT course na sobrang mahal, you can consider business-related courses like Business, Management, Business Analytics, Project Management, or even HR, because mas madaling i-justify na continuation siya ng skills na ginagamit mo na ngayon. Sa visa application, ang pinaka-importante talaga is yung Genuine Student (GS) statement mo—dito mo ie-explain why this course, why Australia, why now, and how it helps your career moving forward.
Kayang-kaya tong i-DIY basta maayos ang school, CRICOS-registered, and malinaw ang study pathway mo.