Hi,
I am holding a reservation for LATAM ticketed flights HEL-MAD-SCL-MAD-HEL, The outbound long haul flight MAD-SCL is operated by LATAM (LA705), but unfortunately the inbound flight is a code share flight LA5410 which is actually operated by Iberia IB6830. So the question is: How to get seat selection done for this Iberia operated flight? As OW Emerald I should be entitled for a free seat selection, but it now seems that I am not able to make the seat selection either at LATAM or Iberia websites. At both websites I can see the flights, but no option for the seat selection for this Iberia operated leg. Did contact the IB Twitter team about the issue, but they were zero help.

Any advice?