Staying at a hotel in Mexico with strong security, all guests must wear a hotel bracelet which inludes a magnetic chip for your room lock. Additionally you cannot walk around the hotel or pass security with wearing it, we have a nearby shul and meals setup by the chabad, is it considered carrying to wear the bracelet?

ב"ה Shalom In Shemirat Shabbat Kehilchata,(19:22- see also Piskei Teshuvot 301:40) he allows for the sake of security reasons, to carry in a place where there is no Eruv to go to Shul , if the object is carried not in its usual way. Meaning, you should place the bracelet in your hat or put in your sock. Some poskim are concerned that since the bracelet is only temporary, it cannot be considered like jewelry which may be worn on Shabbat even where there is no Eruv. I am not familiar with the technical aspect of the magnetic chip, but I assume you have a solution for opening the door on Shabbat in a permitted manner. All the best