This is separate from a dyslexia assessment you may have undergone. The purpose of a needs assessment it to specify precisely how the allocated funding can be spent. This may include assistive technology and other useful equipment
For DSA it can include the number of hours for study coaching (and a brief description of what may need to be covered). The needs assessment can also include an element of mentoring, if a students it struggling to settle into university routines or experiences mental ill-health.
Your needs assessor will advise on the best supplier for you.