Germany does not allow UK travellers proof of recovery certificates for travellers arriving from the UK to enter the country. However, A ‘test and release’ system is in place in Germany which means that, if you are travelling from a risk area you can be exempted from quarantine if you provide a negative test result or indicate that you have recently recovered from a Covid-19 infection when filling in the digital registration. Further information can be found on https://www.gov.uk/guidance/coronavirus-covid-19-test-to-release-for-international-travel.