Building and customizing solutions using Microsoft 365 Copilot APIs and tools
It seems that the issue you are encountering is related to licensing requirements for using agents in SharePoint. Even though you have purchased Copilot credits for the agent, end users still need to have a Microsoft 365 Copilot license to access the agent functionalities. This is because the Microsoft 365 Copilot Chat is available at no additional cost for users with a Microsoft 365 or Office 365 subscription, but it requires the appropriate licensing to utilize agents that incorporate your organization’s data.
Make sure that the end users have the necessary Microsoft 365 Copilot licenses assigned to their accounts to avoid any access issues when trying to use the agent in SharePoint.