With this code, you'll get a SELECT menu in front of the Google search bar to select a prefix. // 1. install js-injection chrome plugin // 2. in google.com, add this code with select 'use jQuery 3' option

Add_Prefix_To_Search_Window.js

const KEY_LAST_SELECTED = "LAST_SELECTED"

const divText = `
  <select id="q-prefix" style="float: left;">
    <option>none</option>
    <option selected>swift</option>
    <option>js</option>
    <option>jquery</option>
    <option>java</option>
    <option>musescore</option>
    <option>logic pro x</option>
    <option>davinci resolve</option>
  </select>
`

$(".SDkEP").prepend(divText)

const gInput = $("input.gLFyf.gsfi")
const qPrefix = $("#q-prefix")

// change last selected option
const lastSelected = localStorage.getItem(KEY_LAST_SELECTED) ?? "js"
qPrefix.val(lastSelected)

gInput.on("keyup", function(e) {
  const optionValue = qPrefix.val()
  if (optionValue == "none") {
    return
  }
  
  let isPrefixCorrect = gInput.val().startsWith(`${optionValue} `)
  
  if ( !isPrefixCorrect ) {
    gInput.val(`${optionValue} `)
    gInput.focus()
  }
})

qPrefix.on("change", function(e) {
  const changedValue = qPrefix.val() === "none" ? gInput.val() : `${qPrefix.val()} `
  gInput.val(changedValue)
  gInput.focus()
  
  // save selected value to localStorage
  localStorage.setItem(KEY_LAST_SELECTED, qPrefix.val())
})

// 검색어 입력하면 나오는 X 버튼
$(".M2vV3.vOY7J").on("click", function(e) {
  setTimeout(function() {
    gInput.val(`${qPrefix.val()} `)
    gInput.focus()
  }, 10)
})