I too thought the lockdown would be a good occasion to worm my bantams in the garden - then I realised how many lettuces I gave them as treats because they were locked in and didn't want to deny them those
My birds on our field get wormed with flubenvet because although the run on our field is very large and kept clean, the birds in there still got worms - saw them in their pooh once!
But you could have a worm count done to see if yours need it? Then worm if you need to?
My birds in the garden, whose run is smaller than the run on the field as they can
trash roam the garden, and who I don't want to lock in for a whole week, now all get an injectable wormer. We do them all in the evening one by one when they've gone to roost and that sorts them out.