About aab because playstore only allow aab not apk

pleas help i am a student i have made a app for our school i need aab not apk to uppload on playstore pleas help pleas

screen

This will download you .aab

i have told i am a student and i am so poor i cant able to buy pro varson pleas help sir pleas
i have completed my project and at last step of upploading i have made an educational app will you pleas provide me an aab file pleas sir pleas