DMAdditions can integrate with Immersive Portals to make BOTI work (lets you see into the TARDIS, and seamlessly walk in without loading screens).
In order for BOTI to work, Immersive Portals must be installed. You can download it from Modrinth or Curseforge.
If you use Optifine, you will need to downgrade Optifine to version G7.
This is because G8 (the latest version for 1.16) changes a class that Immersive Portals is trying to mixin into, which causes the game to crash.
If you have Immersive Portals installed, BOTI will be enabled by default.
If you would like to disable it, you can set disable_boti
in dma-common.toml
#Disable BOTI effect. This only applies if Immersive Portals is installed. Default = false
disable_boti = true