Don't know how much the title sounds good, but here's the story -

I have a tool website on domain suppose abc. com. Now I have plan in making to make country specific tools on same niche and post it on country specific sub domain like us. abc. com or ca. abc. com.

Now I have a wordpress on abc. com/blog to u know publish blogs on same niche, now previously I had plan to create it country specific too like us. abc. com/blog etc. But it's very hectic to manage everything n I asked ChatGPT, it suggested to make the /blog central and managing the urls like this

abc. com/blog/ (central generic topic)
abc. com/blog/us/ (US Based)
abc. com/blog/ca/ (Canada Based) like this.

Now I have no idea how to add this to every link without creating sub-directories actually from one WordPress dashboard which is on abc. com/blog. Tried so many things, still not working, I also thought to put it directly on post editor, but there when I'm including /us/postname, it's automatically getting converted to /us-postname.

Beside creating a category and name it blog, also won't work as the wordpress site itself is on /blog. I can't install wordpress on main site as it's custom coded.

What should I do now? :-D