How do you say Thanks for the well wishes for my birthdays in Chinese?

You can say "谢谢你们的祝福" (Xièxiè nǐmen de zhùfú) to express "Thanks for the well wishes." If you want to be more specific about it being for your birthday, you can say "谢谢你们的生日祝福" (Xièxiè nǐmen de shēngrì zhùfú). Both phrases convey your gratitude for the birthday wishes.