How to get an upgrade on TAP Air Portugal?
Passengers,If you want to upgrade your TAP Air Portugal Flight . TAP Air Portugal provides you four ways to make the TAP Air Business Class Upgrade. To get an upgrade on TAP Air Portugal, you can:

TAP Air Portugal Bid Upgrade-- Use the "TAP Upgrades" service to place a bid for Business Class
TAP Air Portugal Miles Upgrade - Use the miles accumulated to upgrade to TAP Air business class.

Look out for special upgrade offers sent via email or available during online check-in or ask at the airport. act quickly for the best chance.
For more info read blog at the link-

https://www.airlinesgrouptravel.com/blog/how-to-upgrade-on-tap-air-portugal