You will find the DfE guidance here: Suspension and Permanent Exclusions Guidance.
1. Add the Social Worker as a Contact
On the student's profile, you can add the Social Worker as a student contact.
From the student's profile, click the cog next to contact information:
Here you can either Add New in order to enter a new contact's information, or search if you believe the social worker is also associated with another student.
This enables you to link the information on each student's profile, and will ensure any updates in contact details will automatically be correct on all linked student records.
Within the Contact's details, on the Relationship drop down, there is a Social Worker relationship that you can choose.
Insert all of the details and click Add Contact (or Allocate, if linking a contact) at the base of the page.
2. Record them as having a Social Worker
On the student's extended tab, under COVID-19 Information, you can set the question 'Has a social worker during COVID-19' to Yes.
This feeds into the Covid-19 Report at Reporting > Reports > Student (tab) > Covid 19 Report.
It is advised to check all students marked on the extended tab as having a Social Worker, also have the Social Worker's contact details entered on the student profile.
If you filter the 'Has a social worker during COVID-19 column' in this report by Yes (or Y) you will be able to view the appropriate students.