From 8 November 2020 all travellers to Germany have to register online prior to their entry on the website www.einreiseanmeldung.de if they have stayed in a risk area within the last 10 days prior to their entry to Germany. They must also be able to present proof of this registration when entering Germany.
Canada is now considered a risk area with persons entering Germany from Canada being subjected to a 10-days-quarantine (exemptions under certain conditions include a negative test result after five days).
Please take note that quarantine and testing regulations fall within the competence of the federal states so that the respective regulations on the websites of the Ministry of Health of the respective federal state should be consulted.
Please see also the information leaflet by the German Ministry of Health on “Rules for incoming passengers to Germany in connection with Coronavirus SARS-CoV-2” (including digital registration).
In case of technical difficulties with the digital registration, a manual substitute registration form may be used.
In addition, the Q&A by the German Ministry of Health might be of use to you.