Some Resources to Create PowerApps Custom Component

Install PowerApps Cli

https://docs.microsoft.com/en-us/powerapps/developer/data-platform/powerapps-cli

Create and build a code component:

https://carldesouza.com/creating-a-custom-component-using-the-powerapps-component-framework/

Package a code component:

https://docs.microsoft.com/en-us/powerapps/developer/component-framework/import-custom-controls

Publish to production:

https://docs.microsoft.com/en-us/powerapps/developer/component-framework/issues-and-workarounds

Add code component into portal app:

https://www.inogic.com/blog/2021/09/use-of-code-components-in-power-apps-portal/

Extra:

PCF ReactJs Implementation Samples:

https://blog.thenetw.org/2019/06/06/getting-react-and-office-ui-fabric-work-with-powerapps-component-framework/

https://blog.dynamicscode.net/2019/06/26/react-extended-boundary-of-powerapps-component-framework/