The European Commission has published that Horizon Europe will be the follow-up programme to Horizon 2020. The plans are for a €100 billion research and innovation programme. Horizon Europe will start on 1 January 2021. In the next years this proposal by the European Commission will be worked out. Until then: Good luck with your Horizon 2020 proposals.
You can read more here: https://ec.europa.eu/info/designing-next-research-and-innovation-framework-programme/what-shapes-next-framework-programme_en