NARRATOR
Choose which pronouns to use.
choice (PREFERRED_PRONOUNS)
“She, her, hers” {
NARRATOR
Text
} “He, him, his” {
NARRATOR
Text
} “They, them, theirs” {
NARRATOR
Text
}
And to reference it, you would need to use several storylines (but you can also just copy and paste the same storyline but switch the pronouns every time that they are used! It makes use of the choice name to refer to it. Make sure you put the exact name of the choice in the parentheses. 
You can also add more pronouns, but make sure to reference them with more elfis. As shown here, you have 3 options, so you really only need an if, an elif, and then an else. Though if you had 5, you would need an if, 3 more elifs, and 1 else.
if (PREFERRED_PRONOUNS is “She, her, hers”) {
CHARACTER
Oh, there she is!
} elif (PREFERRED_PRONOUNS is “He, him, his”) {
CHARACTER
Oh, there he is!
} else {
CHARACTER
Oh, there they are!
}
You have to mention this same sequence for each time you mention them by pronouns. You can also use labels instead. Here’s what that looks like, using the choice naming method and the if/elif/else. If they all end the same, you can also make a label for that same end sequence.
if (PREFERRED_PRONOUNS is “She, her, hers”) {
goto fem_storyline
} elif (PREFERRED_PRONOUNS is “He, him, his”) {
goto male_storyline
} else {
goto nonbinary_storyline
}
label fem_storyline
CHARACTER
Oh there she is!
#scene here
goto end_sequence
label male_storyline
CHARACTER
Oh there he is!
#scene here
goto end_sequence
label nonbinary_storyline
CHARACTER
Oh there they are!
#scene here
goto end_sequence
label end_sequence
CHARACTER
Oh no! The bag is gone! What are we gonna do?
#scene here
#ending
Hope this helps!