Do we need to have German language certification to get a job in Germany?

I am learning German using free resources, but I am planning to work there in the future.

I am currently working for a US company, supporting their sales through research and automation while working remotely.

So I need to know two things: Do you need to have a German language certificate to get a job, or can I just say that I know German?

And is there a possibility to get remote jobs from Germany directly?

Thankyou!