Lua 错误：'null is not an object (evaluating \'document.querySelector...).click\')'

我正在爬取 https://www.tayara.tn/sc/immobilier/appartements 站点，并需要点击一个 "load more" 按钮。因此我使用了以下 Lua 脚本：

function main(splash, args)
  assert(splash:go(args.url))
  assert(splash:wait(0.5))
  assert(splash:runjs('document.querySelector(".DbXTC b7ygi _1JgR4 _1U08s button").click()'))
  splash:set_viewport_full()
  return {
   html = splash:html(),
   png = splash:png(),
   har = splash:har(),
 }
end

在点击 "render" 按钮后，我遇到了以下错误：

{
"description": "执行 Lua 脚本时发生错误",
"type": "ScriptError",
"info": {
    "line_number": 4,
    "type": "LUA_ERROR",
    "error": "JS error: 'TypeError: null is not an object (evaluating \\'document.querySelector(\".DbXTC b7ygi _1JgR4 _1U08s button\").click\\')'",
    "message": "Lua error: [string \"function main(splash, args)\r...\"]:4: JS error: 'TypeError: null is not an object (evaluating \\'document.querySelector(\".DbXTC b7ygi _1JgR4 _1U08s button\").click\\')'",
    "source": "[string \"function main(splash, args)\r...\"]"
},
"error": 400
}

我错在哪里了？