American Express Platinum card does not offer priority boarding. Priority boarding is a benefit that allows cardholders to get to their seat sooner than general boarding groups. The only American Express card that offer priority boarding is Amex Delta Platinum.

American Express can indeed grant you priority boarding, but it is entirely dependent on which specific card you hold and which airline you are flying with. Amex does not offer a universal "priority boarding" benefit that applies to all flights. Instead, the perk is usually tied to co-branded airline cards. For example, the Delta SkyMiles Gold, Platinum, and Reserve American Express Cards all offer "Main Cabin 1" priority boarding on Delta-operated flights for the cardholder and up to eight companions on the same reservation. If you hold a premium non-branded card like The Platinum Card® from American Express, you do not get automatic priority boarding on all airlines; however, you might gain it indirectly by using the card's airline fee credit to purchase a boarding upgrade or by achieving elite status through the card's various travel benefits and spend. Always ensure your frequent flyer number is linked to your booking and your qualifying Amex card is saved in your profile to ensure the benefit is recognized at the gate during the boarding process.