If a court allows a person to appear via video link, then this can be done either using Teams, or, where a high-quality link is required, then using the facilities in meeting room 7.
If you need access to more or larger video conferencing facilities, then you could use London Teleport located on 233 High Holborn. They have three video conference rooms that can be rented by the hour.
Small 1-3 people £95 + vat per hour
Med 10 people £125 + vat per hour
Large 22 people £155 + vat per hour
All rooms charges include teas/coffees and biscuits.