Can elves change gender?

However, according to Mordenkainen’s Tome of Foes, some elves retain a blessing of Corellon. As part of this blessing, these elves can actually choose their biological sex whenever they finish a long rest. These elves can choose to be male, female, or “neither” based on their moods or feelings. 18-Mar-2018

https://comicbook.com/gaming/news/dungeons-and-dragons-genderfluid-elves/#:~:text=However%2C%20according%20to%20Mordenkainen’s%20Tome,on%20their%20moods%20or%20feelings.