If you want to assign a policy to an endpoint and having trouble doing so, you may follow these steps:

1. Login to your Trend Vision One Console.
2. Go to Endpoint Security Operations>Standard Endpoint Protection.
3. Go to Policies>Policy Management.
4. Click on Create button.
5. Enter your desired Policy Name and click on the Specify Target button.
6. Click on Select button and search the hostname/IP Address of the endpoint you want the policy to be deployed to.
7. Click on Add Selected Targets.
8. Modify the policies you want to configure to the endpoint and click OK.
9. Click on Deploy button.

By following these steps, you should be able to assign the policy to the endpoint successfully.