technical question UC migration

hello i was wondering if you could tell me the timeframe of ESA to UC migration. Once I have applied for UC, and waited the two weeks for the ESA to stop, my question is when do they contact you to ask for ID and ask you to visit the Jobcentre to give them the ID.? For example, how long from applying does it take them to ask you to see them in person, or can you send them the ID online? I am asking this because when I apply, I will be away from home at the other end of the country, and it may take a week or two for me to travel home because I am relying on a family member to drive me home. I dont want to be left rushing home because they need to see me asap. So would you say it takes an exact time or is it variable? thanks. I am not sure if I have explained this correctly. thanks

our child tax credit was moved over to UC and it took a while to set up an account, there is a page where they send you appointments etc and you can reply back........think our appt was booked for 10 days after set up...........