Can I make invisible lights?

I’ve been building in the 21w08b 1.17 snapshot. I’m making an underwater cave house and I need to add some lighting but I don’t want it to show. I’ve been placing glow squids but they keep despawning and they dont actually make light, they just appear glowing. I’m wondering if there is a way for me to add light so it is not visible at all, meaning that just hiding them wont work because of the building I’m trying to light up (as can be seen in the picture). I don’t want to use a plugin, texture pack, or mod (though I could make some exceptions if its the only solution). It would also be great if the light was more dim, since that would look better. Hope ya’ll can help.