Hey there.
This mod uses "freecam" as mod id, which is 1:1 the same as the already released Freecam mod https://www.curseforge.com/minecraft/mc-mods/free-cam https://modrinth.com/mod/freecam. This causes crashes when checking for the mod using FabricLoader.getInstance().isModLoaded("freecam"), and having the wrong one loaded. Related issue: tr7zw/FirstPersonModel#309

Fixed in 1.3.1 fabric

Thanks for the issue, I will look into it.