What the ask is
Your captain asks who is about, and you say. It arrives two ways: a notification in the app, and an email if the club has your address. Both carry the same three answers. You do not need the app to answer.
Nothing about it is binding. A yes is not a promise and a no is not held against you. Change your mind as often as you like, right up to the day.
Answering
Yes, no or maybe. One tap in the app, or one press in the email. The email version opens a page with your fixtures on it and no sign-in to get through, so it works on any phone.
Somebody may also drop the fixture link into the group chat. Tap it and you land on that fixture with the same three answers on it.
Maybe is a real answer. It tells your captain you are close to free, which is more use to them than silence.
If you are picked
You are told, and the team sheet says where to be. The notice names the side, the day and the meeting time if there is one. The night before, you get a reminder.
Reserve means you are not on the sheet and somebody might still drop out. Keep the day free if you can. Your captain will be in touch if a place comes up.
You can be picked whether or not you were asked. Captains ring round on the Friday, and that is a normal week.
If you cannot make it after all
Say so on the fixture and your captain is told straight away. That is the whole of it. There is no apology to write and nobody else to tell.
If the fixture moves or is called off, everybody picked is told, with the new day in the message.
What you can see
Every member sees the fixtures and the team sheet, and how many people have said they can play. Only whoever runs the side sees who said what.
So your no is not on a list anybody else reads. That is the difference between this and a poll in the group chat.
Your own record says what you played and won for which side. It is on your own screen with the rest of your season.