Tap the + (plus) button in the top left corner then Add a control to drop in the relevant shortcut icon: It's under the Vision Accessibility heading, and looks like a car with a row of dots next to it.

这句话的to drop in是做目的状语吗？还是drop sth into的用法？drop in是放入的意思吗？还有这个Add a control是专业术语吗？这句话帮忙翻译一下