I was shocked when I was exposed to AI and have used a variety of services.
I thought most services worked as outlined and that unintended answers or behavior was acceptable.
However, this one was different.

The good news is that in addition to managing appointments and tasks, it works as an AI chatbot.
The fact that it supports Internet access and can answer up-to-date information is very good.
However, it is unfortunate that questions are sometimes incorrectly registered as appointments or tasks.

Here are the problems
It is often assumed that AI will do whatever you tell it your requirements, but FastTrackr will register your schedule or task if you tell it, but you cannot cancel it.
When I contacted support, I was told that this is not possible to prevent accidental cancellations by the AI.
I asked support, “When I asked to ‘cancel the appointment,’ FastTrackr responded, ‘The appointment has been canceled,’ but it was not actually canceled. Can't you cancel the appointment?" I told them.
The answer was as above, but don't you think it is a problem in providing the service to ignore the fact that FastTrackr responded that the appointment was cancelled, when in fact it was not?
We would feel comfortable working on something else if they responded that we had “gone” on what we asked for.
But this is a naturally false answer.
How can we trust such a thing?

Also, when we ask for a reminder, we are notified 5 to 10 minutes after the time.
I thought that once I was notified of a reminder, that reminder was considered complete, but when I asked for tomorrow's schedule, the reminder that I had already been notified of was presented as tomorrow's schedule.
When I mentioned this to support, they said that it was presented as an uncompleted task on tomorrow's schedule, but I have yet to receive an answer as to how the task was completed.

I cannot find any FastTrackr documentation, and both FastTrackr and support are very vague and unresponsive to my questions.

Do not trust your important appointments to such a service.

--- Addendum below ---

I wrote that the notification comes 5-10 minutes 'after' the reminder time.
In other words, even if I ask for a reminder at 15:00, the notification comes at 15:05 or 15:10, so I have to set the reminder with the delay in mind.
Why do I have to consider the behavior of the reminder when setting it?
In response, the message says that "the reminder notifies 5-10 minutes 'before'," so it implies that if I ask for a reminder at 15:00, it will notify at 14:50 or 14:55.
In reality, the notification is delayed, so this is completely false and shows that my review has not been read.

Also, since the topic of "Japanese" came up, I think I have been identified, but despite communicating the language difficulty for phone conversations and opting for WhatsApp communication, the reply states that they will provide phone support.
Furthermore, they said they would check the remaining issues, but I haven't received a response for more than a week since I last sent a message on WhatsApp.