Traveling from Bangkok thu Oman then Germany final destination Canada

According to Visa policy of Oman:

Visitors from any country who hold onward tickets may transit through Oman without a visa for up to 6 hours if proceeding by the same flight.

If you do not meet this transit requirement (such as if your next flight is the next day, for example), then you will need to obtain an eVisa for Oman.

Canadian citizens can enter the Schengen area (which covers Germany) for up to 90 days without a visa, so transit is no problem there.

If you are planning this trip in the near term, you will also need to check country entry restrictions related to the Covid-19 pandemic. Some countries require that some or all persons who enter the country for any reason must self-isolate or quarantine for 14 days. The exact restrictions are changing quickly at this time. Enlisting the help of a travel agent could be a good idea.

At the current time, Government of Canada travel advice for Oman states:

Omani authorities have suspended all commercial flights in and out of the country until further notice.

So hopefully you're planning this for some undetermined time in the future.