In 1983 KAL007 was shot down by the Soviets, as it got lost due to navigational errors and entered restricted airspace. The Soviet interceptors reportedly fired warning shots "which were likely not seen by the KAL pilots", and after then they proceeded to destroy the airliner with an air to air missile.
So, let's suppose you are flying a commercial flight, when a military aircraft catches up to you. If your communication equipment wasn't malfunctioning, you would have already gotten demands to change course and you could have identified yourself, answered that you will comply, and could more easily avert the problem. For this case, let's suppose your comms are down due to technical problems.
You then see you are fired upon (how? smoke trails of a missile flying by? Tracers from guns whizzing past?). It is only then when you realize you got intercepted, and you suddenly realize they just fired warning shots at you.
What now? How could you maximize your chances of survival? I would guess you have to indicate surrender, that you will comply to any instructions, and that you mean no ill will. How can you do that without a working radio? If you just entered a country's territory, the most obvious way would be to change course to the shortest path leading out of that territory, but if you are deep inside, or you are lost, you might choose the wrong heading and make the problem even worse.
Is there a custom how a civilian aircraft can indicate "I yield, please don't shoot me, I will follow your orders!"? And, lastly, how would it differ between the incident happening in 1983 versus 2019?