If you are a member of American Express Membership Rewards you can transfer your Membership Rewards points, in 1,000 point increments to Avianca LifeMiles, the program of Avianca. Normally, Amex Membership Rewards points transfer to LifeMiles at a 1:1 ratio. Through May 31, 2023 you can get 15% more, so 1000 Membership Rewards points = 1150 LifeMiles.
Note, you won’t see as an offer in your Amex account: It’s processed after you do the transfer by LifeMiles.