Domain settings with Ghost

Hello, can someone help me with configuring the URLs settings with Ghost on Render?
I forked and pushed the Ghost image from Render’s Github repo and everything works fine as the description showed in Render’s doc.
Now the main URL blog.mydomain.com is working but the article’s URLs are showing under mysite-dot-onrender-dot-com

Did you set the URL environment variable to blog.mydomain.com? See Deploy Ghost.js | Render · Cloud Hosting for Developers for more details.

I’ll try it now!

Unfortunately, still not working, and worse, I’ve got a deploy error or HTTPS one like the website is not secure