Ask your employer for Statutory Sick Pay.
Employees can use the online SC2 form to request Statutory Sick Pay from their employer after being off work sick for at least one full working day. You must provide details of your sickness and employment information to your employer to help them determine your eligibility. The form should be completed in one session and submitted directly to your employer once finished.
Source: https://www.gov.uk/guidance/ask-your-employer-for-statutory-sick-pay. Summarised automatically from the official source — general information, not advice.