post_name vs post_title

post_title is the post’s actual title. post_name is that post’s unique part of the permalink – sometimes called the slug.

how to I make them the same?

Why would you want to?

Because the ‘slug’ has gone screwey. I’ve got urls like:

https://www.domain.com/%e5%8a%9e%e5%85%ac%e5%ae%a4%e6%a1%a3%e6%a1%88%e5%92%8c%e5%b7%a5%e4%bd%9c?lang=zh-hant

And it would be correct it aligned with the post title:
https://www.domain.com/日常工作/?lang=zh-hant

I’ve tried editing the post_name but that just results in 404 page not found errors