Contracting 行っておいで to 行っといで
Grammar: Colloquial and Casual Speech » Contracting 行ってお出で to 行っといで
行っておいで, a casual way to send someone off, may contract to 行
Examples
Going to say good morning with 行っといで

Ninako confessed her feelings to Ren, even knowing he already has a girlfriend and would turn her down. After not seeing Ren during summer break, Ninako wonders if she’ll still be able to greet him normally. After a boy she turned down greets her normally, Ninako feels more confident.
- つかさ:
- 「ホラっ 仁奈子
( 今度( はあんたの番( だよっ」- “Hey, Ninako, now it's your turn.”
- 「そろそろ連
( くん 来( るんじゃない?」- “Won't Ren being coming soon?”
- 「行
( っといで!!」- “Go for it!!”
- “Hey, Ninako, now it's your turn.”