Experiencing the same issue others have reported regarding accessing the reservation with TK that was booked thru Avianca.
Called TK and they told me they can't access the reservation because the e-ticket number does not start with 235. Tried feeding in my 134xxxx eticket number into the TK app and got an error message indicating that due to the sales channel it was booked it cannot be viewed/accessed.
Called Avianca customer service and surprisingly was able to get and they supplied me with the TK PNR and was able to access it on the app.
Wish more airlines would start supplying partner PNRs in the manage booking section.