/gametest run codex:codex not work.

[kaichungss1]

I followed the steps in the README, but when I run the gametest command, I encountered the following error:
could not find test with name 'codex:codex'.

But when I changed the minecraft/server in the manifest.json to 1.1.0-beta, I was able to proceed, but still encountered the following error:
onTestFailed: codex:codex - TypeError: not a function at CodexGame (CodexGame.js:31) at <anonymous> (main.js:24)