The very early grills have a CNC cut hole with vermeculite insulation in the hole. It can easily be removed with a hammer and screwdriver.
This adapter from BBQ Guru can be tapped into the hole with a hammer and it's snug and tight..
https://www.bbqguru.com/product/1-3-8-adapter
The hole in the faceplate is CNC cut for this adaptor.. Set the adapter into the hole at a little angle, then tap the high side with a metal hammer. It will click/snap into place and will be tight enough to require a happer to remove it.
You will also need to get a plug for the sleeve.
They come in both colors
https://komodokamado.com/collections/23-ultimate-spare-parts/products/bbq-guru-plug-nat-teak
https://komodokamado.com/collections/23-ultimate-spare-parts/products/bbq-guru-plug-black-1