my treat 我请客；我宴客；是我请客

【例句】
We can make it a working lunch this afternoon, and I'll order some Chinese food for delivery. It'll be my treat.
我们今天下午安排一个工作餐，我去订一些中餐外卖。我请客。

I'd like to thank you for your help. Let's go get dinner together. My treat!
我还得感谢你的帮忙呢。走，我们一起去吃饭。我请客！