Error in mounted hook: "TypeError: Cannot read property 'appendChild' of null"

[DaTongDXM]

The code I run contains a component that needs to add a canvas tag to the dom. `

• const oDiv = document.getElementById(self.table.id);
• const canvas = document.createElement('canvas');
• oDiv.appendChild(canvas);
  ` When I run it, I report an error： Error in mounted hook: "TypeError: Cannot read property 'appendChild' of null" How to solve this problem