The Government's solar panels incentive scheme came to an end on 31 March this year. (People who were already in the scheme continue to receive payments for feeding electricity into the National Grid but you can no longer sign up to the scheme).
However, from January of next year all energy suppliers (except those with fewer than 150,000 customers) will be obliged to offer a feed-in tariff, whereby they pay people who feed energy into the system. (It's a Government incentive, backed by law, called the Smart Export Guarantee). It will be up to those companies to determine the prices they pay for electricity but the only company that's announced a tariff so far would seem to be paying roughly the same as under the former Government scheme.
Relevant links:
https://www.moneysavingexpert.com/utilities/free-solar-panels/
and
https://www.moneysavingexpert.com/news/2019/06/new-scheme-to-offer-payments-to-households-with-solar-panels-/
Be very wary of what salespeople tell you though:
https://www.bbc.co.uk/news/uk-england-49566130