Query about a feature of iOS about hiding some portion of a screenshot - possible ?

Hello experts and knowledgable members of the forum, This is a query of iOS screenshot modification feature related rather than iPad itself, didn’t find any dedicated forum related towards iOS hence posting this here. As the title suggest I’ve lots of screenshot need to forward to the people where I need to hide a certain portion of the screenshot in multiple places...the best and quickest way to draw a rectangle with filled up inside or add solid colour to the rectangle later. In iPad OS I find once the screenshot taken I can draw a rectangle but can’t filled up easily. I need to manually colour the whole rectangle by using the Pencil. My concern here Doing this way always not accurate and very time consuming - This lack the touch of perfection / professionalism. Below is the screenshot perfectly demonstrates my concern. I want the black rectangle portion to be filled perfectly without manually doing via pencil - So no black ink outside the border / perfect shape etc etc And complete the task quickly - (1) Is there the feature available in this program which I can’t find ? (2) If not is it possible to implement ? I don’t want to use another program to do this as I need to black out at least 20 - 25 such screenshot at multiple places as the the needs arise.....Please let me know if it possible.