You need an ETA for American Samoa if you have an Irish passport

Travellers need a travel authorization to visit American Samoa for Business or Tourism. Visa-exempt visitors entering American Samoa must obtain an Electronic Travel Authorization (eTA). Travellers can submit the eTA application online. Once the application is approved, travellers receive their eTA confirmation electronically. An eTA is electronically linked to a passport. If travellers receive a new passport, they must apply for a new eTA. A valid eTA is required to board the flight. If the eTA is expired or doesn’t match the traveller’s passport information, travellers will not be able to board their flight.