Back in the mists of time I first went to the job centre when i left uni and they gave me a number you had to phone up to go on jobseekers allowance. You called them up, gave them the details then they processed your claim. Then I don't quite remember the next step because its been so long ago but you had to go to an appointment at the job centre where they would discuss what you were doing to look for work. I think they are more strict on this now and have sanctions and stuff. It also takes longer to make a claim for universal credit.
It could have changed now because that was nearly 15 years ago and with beer virus i think the job centres are all closed.
Neetbux isn't what it used to be. They are shit hot on making sure you are looking for work these days. It isn't that much money either. When i was signing on it was maybe £100 every 2 weeks and you had to attend a review at the jobcentre. You could do part time work and still claim something to top up your earnings. You had to bring your pay slips to your jobcentre appointment and they would calculate how much to deduct but it generally worked out favourably. I used to make extra money delivering leaflets, doing a few hours picking at a fruit farm and selling tickets at football matches. Then i got a job working on building sites that was worth about £500 a month cash.