If you have missed the deadline you can still apply for EUSS if you have reasonable grounds. The list of ‘reasonable grounds’ is not exhaustive and includes:
Children
Care leavers
Where adults lack the mental / physical capacity to apply
Where there are serious medical conditions
Victims of trafficking
Abusive / controlling relationships.
Other compelling or practical reasons
An application should still be accepted past the 30th June deadline but seeking specialist immigration advice and representation is strongly advised if the deadline is missed where, a person:
may have been unaware of the requirement to apply to the EU Settlement Scheme by the 30 June deadline
may have failed to make an application by the deadline if they had no access to internet
had limited computer literacy or limited English language skills
had been living overseas