Just wanted to give an update. Scheduled my antigen test online by creating an account at…read morefarmacias del ahorro (600 Las Casas, Oaxaca Mexico)for 299 pesos scheduled within 24 hours(required) of my flight. I used my hotel's address to create my account and you will use this address when you pay/schedule online. You go 15 minutes early to the retail part of the pharmacies to verify you have paid online with the information confirmation sent to your email. The Doctor will verify information and have you sign and date form(this is the limit of his English, the technical aspect). The test takes 30 seconds, you wait 5 minutes for the physical copy and about 20 minutes for email copy. You can pay less at other laboratories, but beware like the Spaniard at my hotel who paid 230 pesos, but still did not receive his verification the next day. The last I saw of him, he was going to the site to find out why, a few hours before takeoff. No problems getting through the Airport. Recommend.