Inviting Google Cloud identity or Workspace users to a Project

You can follow this link if you have if you don’t know how to create the user in Google Cloud Identity

Make sure that you have created the user in Google cloud identity.
Go to Google console and select your project
Search for Identity and Access Management service
click on the Add button
Now you will need to enter the user principle which is nothing but the e-mail ID of the user which you created in cloud identity
You can select a role as a basic Viewer role
then click on the Save button
This process adds the user to your project and gives the user a viewer permission or a reader permission on the projects and the services which are hosted inside this project

Tutorial