I won't be able to see you... but happy birthday anyway!
Happy birthday! I'm so sorry I won't be able to see you on your special day, but I hope that wherever you are, you're having an amazing time.
I wish I could be there with you—but from here, in the distance, I'm sending my love and wishing you a happy birthday.
I know I'm not there to celebrate with you, but I wish I could.
Even though we're far apart, know that I'm thinking of you and wishing you the best on your special day.
I'm writing this from far away, so I won't be able to see you on your birthday. But even from here I want to wish you a happy birthday! Have a great day!