Sputum sample when on Brinsupri

I've been on Brinsupri since last November. Thankfully, my inflammation and sputum have decreased. I need to send in a sputum sample to NJH next week and have no idea how that's going to happen. They want at least 5 ml and most days I can't get that much up. I've read tips and hints but most of those are pre-Brinsupri. I know I can't collect a sample over two days. Anyone else in this position? Thank you! Jennifer