Add SPFx Web Part to a Full Width Column
Introduction
In the communication site we can create a Full width Column that allows us to add a web part that will have full On the communication website, we can create a full width column that allows us to add a web part that will be full width. Once created, we will see a list of Web Parts that can be added to the section, not all Web Parts can be added to a Full Width Column Section.
Here the screenshot how it look like after added a Full with Column to a page.

How to allow an custom SPFX web part can be add to a Full width Column
We can allow our SPFx web part to be added to Full width Column, for that we must have to add a new property to our web part manifest file, called “supportsFullBleed“, this property is type boolean and have to set to true.
Here sample of manifest file with property enable.
{ "$schema": "https://developer.microsoft.com/json-schemas/spfx/client-side-web-part-manifest.schema.json", "id": "bd3165a7-de0f-46bf-b961-7c07b0a5b7ad", "alias": "NewsWebPart", "componentType": "WebPart", "supportsFullBleed": true, "version": "*", "manifestVersion": 2, ... }
After deploy the web part , and fi we go to our page that have a Full Width Column Section, you will see our web part in a list of web parts allowed to add.
Here a sample:

Thanks for reading!