I’ll buy you a meal.

我顿我请你。

It’s on the house.

饭店老板请客。

It’s on me. / This one is on me .

这顿算我的。

I’ll get it .

我来买单。

It’s my treat.

我来买单。

I’ll buy you a dinner.

这顿我请了。

I’ll buy you a drink.

请你喝一杯。

No worries，I got this.

没关系，这轮我请。

I’m buying the second round.

我请大家喝第二轮。

Don't worry about it, it’s my treat.

放开了吃，我请客。