Life in uk test registration - Middle name

Hi, I am applying for Life in the Uk for ILR. Life in uk registration form says please enter middle name if you have one, any mismatch in the name would result in rejection for giving the test. My passport has name format
Given name - first name fathers name
Last name - Surname

BRP Card name format

Last Name - 1st line
First Name Middle name - 2nd line

The question is should I just enter last name as last name and first name as first name + Middle name OR enter first name, last name, middle name separate while registering for Life in the uk test, what is the name format of the UK BRP card?

Follow the format of the document you want to use as ID to sit the LIUK test