2👍
I found the answer here https://github.com/wkhtmltopdf/wkhtmltopdf/issues/1645 only need put the doctype to each html.
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<img src="http://www.someplaceintheworld/some.png" alt="some logo" />
</body>
</html>
Source:stackexchange.com