input prompt
Computing term for a prompt that encourages or facilitates user input, such as a command-line prompt or a dialog box.
An input prompt appeared on the command line.
The loanword プロンプト is also common for 'prompt' in computing contexts, while 入力促進 is a native compound that explicitly means 'input facilitation'.
Compound of 入力 (input) and 促進 (promotion, facilitation).