A 7 year old kid is usually too busy playing and not paying attention that they will hold their urine in for awhile until they have to go to the toilet or go in their pants.
I remember being 6 and 7 years old and younger and although I was out of diapers and potty trained I would still sometimes wet my pants.
It kept on and on until my dad decided that either I used the toilet or I wear diapers again.
So when I was 6 years old my dad put me back in those plastic backed pampers that were thick back then and I had to wear just the diaper around the house without any pants even when family came over.
I had to also go outside wearing nothing but the diaper which at the time I hated him for it.
But he did have my best interest in mind and he loved me and the diapers were more sanitary for me to wear and use then just peeing my pants.
So after wearing the old plastic backed pampers diapers all those years ago I started hating the feeling of wearing the diaper and would go to the toilet instead.
I also hated getting the diaper changed wherever we were.
When out shopping or at the park my dad would change my diaper in the back of his truck bed and then I decided that it was getting embarrassing.
So that stopped me from peeing my pants.
Yes I was peeing my pants basically on purpose because I didn't want to go to the toilet but I found that having my playtime interrupted every 3 hours or so to have my diaper changed was worse.
It was easier and faster to use the toilet then have to get laid down on the floor or in the back of my dad's truck, have my shoes and pants removed and then wiped and cleaned.
So I would recommend that you do tell your kid that you're gonna diaper them again if they don't use the toilet.
Get some diapers and show them to them and if they still wet their pants and have no incontinence issues then diaper them and they may get the hint.
Tell them that it takes more time to change their diaper than it does to just pee in the toilet.