what should/shouldnt do to ensure i get age of stars ending after i do rannis quest? SPOILERS

so in the story ive beaten morgot and then i decided to clear mt gelmir and cealid which i did and also did rannis questline(goated npc) and ik to get the age of stars ending i just summon her after elden beast

but today i was reading the titles of the 6 endings just to get an idea and i heard that if you talk to an npc named 3 fingers you get the frenied flame/chaos ending

so how do i ensure to get age of stars? if i talk to 3 fingers am i doomed???


PLS NO SPOILERS AND DONT PUT A COMMENT WITH SPOILERS IN THE BLACK SPOILER TAG BC THATS LIKE BEGGING ME TO PRESS IT