How to program an FMC if the database is missing the arrival airport? Let's say you are in a 737 flying to Geita, Tanzania, as you can see this little airport/airstrip has an IATA code, but not an assigned ICAO code. What should you enter into the FMC if I want to fly to that airport?

And in general, how to navigate to an airstrip that has only an IATA code?
If the arrival is missing:



If the departure is missing:



And here are the affected items:



Source: 787 FCOM.