We can't find the 'Use Lead Nurturing Agent' Permission Set assigned to the correct user.

Hi @Dinesh Somvanshi -  

• Make sure Agentforce is enabled in the Playground.
•  Check Setup > Agentforce for Sales and confirm Lead Nurturing is enabled. 
•  Wait a few minutes after enabling it, then refresh Setup. 
•  Make sure you’re using the Playground created specifically for this Trailhead module. 
•  If Lead Nurturing still doesn't appear, create a fresh Playground and start the module there. This is often caused by the required Salesforce Go provisioning not being available in the current org.