That is why you use jq --arg for the input instead of crafting it by string concatenation.

    data=$(jq -n \
            --arg title 'what"ever' \
            --arg endpoint 'foo"bar' \
            '{
            "title": $title,
            "endpoint": $endpoint,
            "enabled": true
    }')

If I really had to get some JSON into a Bash script, and I couldn't just stick it in a file, I'd probably use a "heredoc" something like this:

    $ my_json="$(cat <<EOF
    > {
    >   "foo": "bar",
    >   "baz": 42
    > }
    > EOF
    > )"
    $ echo "$my_json"
    {
      "foo": "bar",
      "baz": 42
    }

But I definitely didn't remember how to handle the closing paren and closing quote correctly, and I had to google for an example just now. So I'm not allowed to say this is easy to remember :)