Formalising a trust

The company that have arranged my parents Will has notified us that we need to Formalise the Trust with land registry. We lost my father in 2020. I did the probate for my mother. I am an executor and also hold LPA for my mother for Finance and Health/Welfare. I don't remember contacting land registry but i may have done. How can i formalise the trust? What paperwork do i need to infill and can i submit this online? Is there a fee/charge? Thankyou

Lesley - we don't register/record trusts specifically so I'm unclear as to what they meant by 'formalise the trust' with us
Sometimes such interests are protected on the register and perhaps they meant the guidance provided by PG 24 Private Trusts