canonical URL, trying to figure this out! Options

[pixie.susan]

First, I want to say I'm mostly a beginner at making a website. I know I should have a responsive site, but right now, I don't. I'm working on my first one, but I want to do this in the meantime: Use a canonical tag to tell Google that I have identical desktop and mobile versions of a six-page website.

I've Googled this endlessly today, and I can't tell who knows what they are talking about because I have found the complete opposite information on different websites of what tag goes where (and the tags they are recommending look different, too).

Here is what I understand. I need to tell Google that one site is the main site and that I have duplicate pages for the mobile site What I can't figure out:

1) Which tags go on the main site, and which go on the mobile version?

2) What those tags should look like?

Right now, it's my understanding that this tag should go on the desktop/main version:

<link rel="canonical" href="https://mysite.com/index.html" />
<link rel="alternate" media="only screen and (max-width: 640px)" href="http://mysite.com/mobile.html">

But another site tells me I should have this on the main/desktop page:

<link rel="canonical" href="https://www.mysite.com/index.html" />
<Link rel="alternate" href="https: //m.example.com/mobile.html" />

And some say to put this on the mobile page:

<linkrel="canonical"href="https: www.mysite.com/index.html"></linkrel>

(different tags: <link rel= and <inkrel= does it make a difference?)

Can someone help me and let me know what goes where in simple language? I do understand that I need to do this on all 6 pages and I would of course change the URLs depending on the page name.

Many thanks for any help.

Susan