A NodeJS package produces template data of MCBE NBT. It can produce initial NBT data of blocks, block entitie and entities.
This package based on MCBE 1.20.
npm i project-mirror-registryconst PMR = require("project-mirror-registry")
, NBT = require("parsenbt-js");
// Returns a ParseNBT.js object with proxy
var a = PMR.createBlockEntity("command_block");
a["str>Command"] = "say Hello Minecraft!";
// Then you can put the NBT data into anywhere supports ParseNBT.js objectSee api.md.