Does the "referr a friend bonus" be taxable?

I got some money from company like Octopus energy and Top-cash-back, etc., because I referred friends to use their services. I am not a sole trader. Do I need to put such income into the self assessment? Which part of the form should I put this income in? Thank you.

Hi Kin Sun Cheung,
It doesnt meet the criteria here:
SAIM8020 - Annual payments: meaning of annual payment
So you do not need to declare it.
Thank you.