I do not know if the title left doubts, but I will show the code that is generating the button, and I need the variable to be surrounded by quotation marks like this: onclick = "anything (value)" -> NOW
onclick = "anything ('value')" -> HOW I WANT
$btn = '<button type="button" onclick="button('.$id.')" class="btn blue-madison btn-sm" style="margin:0px;">Gerenciar</button>';