You know how, in many movies and TV shows, people planning to get together tend to leave it a bit vague about precisely when this meeting is to take place.
One person says "Let's have dinner tonight" and the other person says "OK, let's do."
And that's all the planning we hear about.
It's nuts. In real life, it helps to specify a time and a place.
OK, you could argue that a follow-up text exchange is implied. But this lack of precision has been a part of films and TV since long before the modern era.
Everybody should be like my friend. When I propose meeting somewhere at 11:30, my friend writes back "See you at 11:29."
That's how you do it.