Most of my writing is in french so codes are a little different, but usually in English it's fine to use "he said" "she said" "they said" dialogue tags 80-90% of the time because the average reader sort of filters those words out when reading (which is not the case in french, don't use "dire") and sometimes you don't need dialogue tags at all thanks to context clues, what the character is saying and how they're saying it..
When you have multiple characters of the same gender or your character is doing a specific action and it needs to be clear what character is doing what, if you're in a 1st person POV book you can use an epithet that shows what your POV character thinks of the character talking (like if a child is getting scolded by their teacher it could be "the headmaster said" instead of "Mr Baker said" because the kid sees the authority figure more than the person when they're getting told off for example).
When I'm scripting my comic, like in my google doc that only I will see it's in sort of a prototype stageplay format so like others have said "[character initial]: blablabla" and then didascalies in italics.
So i'll have K= Khay, A= Alice, AD= Aide, F= Finn and S= Sarin.