actually the egyptian azhar adviced to cancel ramadan all together... fasting does hinder ur imune system in the first days hence it would be a sin against your body to fast (plus u would endanger the people near you)... also its better to keep ur mouth wet... they advice to do the fasting thing after... (also you have no clue if you are sick or not with this corona thing going on)

doing the donation thing and being generous and stuff tho might be now more important than ever... as many people have lost their source of income with this lockdown and go hungry...

source: https://www.tagesschau.de/ausland/corona-ramadan-101.html