Entry into the United States is not guaranteed even with an ESTA (Electronic System for Travel Authorization) that has been authorized.
A Customs and Border Protection (CBP) officer at the port of entry makes the ultimate decision to accept a traveler. It is only an authorization to travel to the United States under the Visa Waiver Program (VWP).

Based on the details given on the ESTA application and during the port of entry inspection, the CBP officer will decide the duration of the stay and the traveler’s eligibility.
The policeman could also request that the passenger present further documentation or information.

It’s crucial to remember that even if your ESTA is accepted, this does not mean you will be allowed entry into the US.
You could be refused entry and sent back to your country of origin if a CBP officer decides that you are not permitted to enter the United States.

Even with a granted ESTA, admission may still be denied for a variety of reasons, including giving false or misleading information on the application, having a criminal record, posing a security risk, having a history of overstaying, having a possible public charge, and more.

To ensure that the procedure goes successfully, it is advised to have all necessary paperwork on hand, to be truthful and transparent in your ESTA application, and at the port of entrance inspection.