I have a shared hosting account on which I host my websites, of course, some addon domains pointing to my shared hosting.
I just bought a SSL certificate on goDady too, and i follow the tutorial to install the SSL on the addon domain named xaynhatro.net, but after that when i visit the link https://xaynhatro.net there's an error said that this site is not secure, can any one tell me what's wrong and how to fix it?
Shame you had to purchase your SSL certificate. It's still possible for you to install the SSL on an addon domain.
I did that the first time around when I first purchased the SSL. Then got fed up with the costs and got it for free.
My guide below may help you install your SSL on your subdomain. Ignore some parts are they won't be relevant to you.