Referral £50, didn't see an option when signing up

Hi all
Is it still possible to get the £50 referral bonus, if I didn’t see an option to refer when signing up.

You were supposed to click the link that the person referring you sent to you.

If you have only just done the sign up, cancel the switch, wait three days, reapply using the link.
Bulb wont apply the bonus retrospectively (I know, I tried ringing them!)