Do I need my BRP card when applying for benefits

Hi I have lost my BRP card but still have the paperwork it came with. I also have my pakistani passport, NADRA card, and other documents such as my NI number.

I have recently split up and live with my 2 children. I will like to know if I need that BRP card to apply for any benefits.
Also how do i apply for a new BRP card and what are the costs?

The benefits office will want evidence of your immigration status, in the form of a BRP as this is your visa.

When did you lose it?

I lost it as I was moving out few weeks ago. At the moment I am living at my uncle's house but I need to move out and I am dependent on some sort of benefits to help me pay rent and maintenance of children.
Do i need to apply for a new one and how?

https://www.gov.uk/biometric-residence-permits/replace

What is your immigration status in the UK?

I have an ILR