The NHS Test & Trace feature, will ask visitors if they have the app installed on their smart phone. If they answer yes, the system will show your site QR code on the screen for the visitor to scan with their phone.
To complete this task on the Dashboard simply follow the steps below
Log into your Dashboard
Settings > Branding > COVID Track & Trace
Upload your PDF into 'COVID Trace PDF'
Click Save Branding
If this option is not available you need to enable this feature following this article first.