Ok drinks while fasting...

Sure, why not.
That was a random answer. What do you expect from fasting?

Time restricted eating/feeding doesn't have anything to do with what you eat or how much you eat so breaking a fast has nothing to do with that but does with forgoing food all together for a specific amount of time like a day, two days, 3 days, a week which would be considered fasts, and that is what your question is in reference to, just in case you didn't realize it.

The benefits of actual fasting are cumulative from actual fasting for a lifetime. I suspect your here for weight loss and who knows what kind of fast your doing or how long you've been on one or if you intend to make it part of your life but whether you drink something with calories or not over the course of a few months, 6 months, a year will make no difference in the big scheme and I suggest you do what gives you the best chances for sustainability for your weight loss journey. But to answer your question anything without calories is pretty much allowed working on the premise that 0 calories won't trigger physiological mechanisms, but the jury still out on sugar substitutes, especially in the gut.

Lots of water, warm water can be filling too. I hear tea plain and black coffee but I think lots of water is key.

From a fatloss perspective fasting does nothing positive, in fact when coming off a fast many people are ravenous and end up eating back all the calories. Fasting has been touted as having a myriad of health benefits however the jury is definitely out on that.