How do I put more iCloud storage on my phone

Upgrade your iCloud storage plan - Apple Support

You should note that iCloud storage is not actually on your phone, if that's what you were thinking. iCloud storage is online and accessible to any device signed into the account: but the storage on an iOS device cannot be increased. Tesserax has shown you how to increase your iCloud storage, but if your phone is running short of space doing this won't make any difference.