I can only find the original agreement and login for on Barclay website. Is there a place to login and check the remaining payments and balance?
...you should receive a statement once in a while, from Barclays which shows how many payments you have left. I think they send it out every quarter as I received one in October 2019 which confirmed that I only had 8 (well, it was 8 in October obviously - it's only 4 now!) payments left to make before I officially own my iPhone XS!