Can't login to Give website

Hi,
I have paid for the Braintree Give Plugin, and am trying to login to my account to download the Receipt.
I am trying to login using the confirmed details that Give sent through when I set up my account, but the Give website is saying “ERROR: There is no user registered with that email address.”

I have copied and pasted the email directly from the Give email confirming the setup of my account.
Could you please tell me what I am doing wrong, also if this will affect the functionality of the Give and Braintree plugins on my website.
Thanks.

https://www.ads-software.com/plugins/give/