If you have already booked a flight with Avianca Airlines and want to choose your seat, you can do so by following these steps:

1. Go to Avianca's website and click on the "Manage your booking" option.
2. Enter your reservation code and last name to access your booking.
3. Click on the "Select your seat" option and choose your preferred seat from the available options.
4. If you are not satisfied with the available options, you can try changing your seat by selecting another available seat or by checking back later to see if any better options have become available.
5. Once you have chosen your seat, confirm your selection and save any changes to your booking.

If you are having trouble with Avianca airlines seat selection or making changes to your booking, you can contact Avianca's customer service team for assistance. They will be able to help you with any issues you may have and answer any questions you may have about your flight or seating options. If you want to know more you can read the full blog.