Lua script fails but the JS works in console - lua

Question

I have this very basic lua script that returns an error, but running the querySelector directly in the console works just fine.
Any hints on what is wrong with my lua?
function main(splash, args)
assert(splash:go(args.url))
assert(splash:wait(1))
assert(splash:runjs('document.querySelector("button.btn.btn-primary.btn-show-rates").click()'))
splash:set_viewport_full()
return {
html = splash:html(),
}
end
BTW: website is here
Error log:
{
"type": "ScriptError",
"error": 400,
"info": {
"type": "LUA_ERROR",
"line_number": 4,
"error": "JS error: 'TypeError: null is not an object (evaluating \\'document.querySelector(\"button.btn.btn-primary.btn-show-rates\").click\\')'",
"message": "Lua error: [string \"function main(splash, args)\r...\"]:4: JS error: 'TypeError: null is not an object (evaluating \\'document.querySelector(\"button.btn.btn-primary.btn-show-rates\").click\\')'",
"source": "[string \"function main(splash, args)\r...\"]"
},
"description": "Error happened while executing Lua script"
}

Answer 1

Turns out it was kinda simple...
A slightly longer "wait" and changing to document.querySelectorAll made it work. Final code here:
function main(splash, args)
assert(splash:go(args.url))
assert(splash:wait(5.0))
assert(splash:runjs('document.querySelectorAll("button.btn.btn-primary.btn-show-rates")[0].click()'))
assert(splash:runjs('document.querySelectorAll("button.btn.btn-primary.btn-show-rates")[1].click()'))
assert(splash:runjs('document.querySelectorAll("button.btn.btn-primary.btn-show-rates")[2].click()'))
splash:set_viewport_full()
return {
html = splash:html(),
}
end