Sandbox Account: https://mp.weixin.qq.com/debug/cgi-bin/sandbox?t=sandbox/login
Official Account: https://mp.weixin.qq.com/
Test Official Account API: https://mp.weixin.qq.com/debug/cgi-bin/apiinfo
Official Document: https://mp.weixin.qq.com/wiki?t=resource/res_main&id=mp1421141115
This course's link: https://wechat-development.teachable.com