How Do You Manage the Load Order With Scripts In Header and Footer?

I know how to reorder scripts with the drag and drop editor, but this isn't enough for this case, because Apple is smarter everyone, and for my project to function on iOS, one script needs to be after the body. How do I accomplish this without manually doing it? (I can't test easily this way.)

Edit: https://bootstrapstudio.io/forums/topic/ability-to-add-custom-javascript-scripts-to-buttom-of-page/

This doesn't seem to work, as you can't put custom code there.