Given the task definition and input, reply with output. Given a travel related situation, and given a specific question about the situation, summarize the question into a title

My Icelandair flight to Denver via Keflavik was rebooked by the airline to a direct BA flight when the first leg was delayed (which would have meant missing my connection).

I am a member of the BA Executive Club: can I claim Avios or BA Tier points for this rebooked flight? The BA website has a page to claim missing Avios, but this requires a ticket number which I don't have (it's not on the boarding pass).
Claiming Avios / BA Tier points for a rebooked flight