Assalamu alaikum ustadh, if someone made hijrah to a muslim land and after seeking ilm he wishes to go to the west to give dawah, and stay forever what is better for him and has more rewards?

This has to do with the need, if he is needed there, then he goes and gives dawah If he is a person of knowledge, safe in his religion, able to practise it openly, and his daʿwah there truly happens without a greater harm or fitnah upon him.