Why the json data become null when insert into database through Rest Api?

System Information
  • Strapi Version: v5
  • Operating System:
  • Database: sqlite
  • Node Version: 18
  • NPM Version:
  • Yarn Version:

I encounter a problem when I create the json content type through the Rest Api. The inserted data just become null in the database. But I can create the blocks type content using the Admin panel. Is any one know what is going wrong? Thanks First