To get the grant of £350 for an EV charger it has to be installed by 31st Mar 2021 see from scheme details above and para copied from that doc below.
“From April 2022, the Electric Vehicle Homecharge Scheme (EVHS) will no longer be open to homeowners (including people with mortgages) who live in single-unit properties such as bungalows and detached, semi-detached or terraced housing.
Installations in single-unit properties need to be completed by 31 March 2022 and a claim submitted to the Driver and Vehicle Licensing Agency (DVLA) by 30 April 2022.”