KGG,
Info below is from this web site: https://www.anguilla-beaches.com/covid-19.html

All visitors to Anguilla who are eligible to be vaccinated against COVID-19, are required to be fully vaccinated at least three weeks before arrival (i.e. persons 18 and older). Exemptions include: Pregnant woman and children under the age of 17 years old. No medical exemptions will be granted.

Requirements [for travel to Anguilla]

Submit your application for travel
Submit negative Covid-19 test taken 2-5 days before travel
Accepted tests...
Reverse Transcription Polymerase Chain Reaction tests (RT-PCR)
Nucleic Acid Amplification tests (NAA)
RNA or molecular test
Antigen tests completed via a nasopharyngeal swab
NOTE: Self-adminsitered home tests and antibody tests will not be accepted
$50 USD fee for testing on arrival
You will be tested upon arrival. You must remain in place until the receipt of your negative arrival test result (~24 hours).
If your test is negative, there is no requirement to quarantine. However, returning residents and visitors staying in Anguilla for more than 8 days may be required to undertake a day 4 test.