How to proceed if email asking for a recommendation letter hasn't gotten a response after 3 weeks (during COVID-19 pandemic)? I know this question has been asked before but here is the Covid-19 Pandemic Edition:

I emailed my professor asking if they would consider writing me a LOR almost a month ago and haven't gotten a response. Normally after a week or two I'd sent a follow up email but email etiquette seems a little different right now due to the Covid-19 pandemic.  I don't want to pester them or seem out of line but I would really like a response and am not sure what to do. I'm not sure if I should ask again because this professor is not planning on teaching next semester and I would imagine is busy working on other summer projects. And, like most of us right now, is probably trying to deal with the many uncertainties brought about by the Covid-19 pandemic. I did very well in the class but the last month of the semester was very disrupted due to coronavirus and all classes had to be made entirely virtual, so I'm not so sure that I'd stand out as a well-performing or memorable student as much as one would under normal circumstances, but I'm not sure who else to ask at this point. I need the LOR in the fall so the deadline is still several of months away. Should I wait another week or two and see if I get a response? Should I send a follow up email now or just assume that no reply means no?
Send a follow up email reiterating your request and the deadline. It's likely the professor has just lost your email in their inbox. It happens, pandemic or not.