You need to present a negative covid test that was taken within 72 hours of arriving at where you are staying. The text posted below is taken right from the French St Martin website, and I have also included a link below the text where you can see the actual website.
"
For travelers with accommodation on the French sideIf you are staying in an establishment on the French side of the island, a negative test result of less than 72 hours is mandatory."
St Martin - covid info linkScroll down about half way to immediately before "Grand Case Espérance Airport"
Just take the test at home before the 72 hour period. It doesn't specify PCR or Antigen so just go with the easiest that works for you and present the results to where you are staying. They won't have access to EHAS so why post to the website.
