Can I transfer my iphone storage to iCloud storage to free up space

iCloud storage can only help in a limited way with a shortage of storage on the phone. See the information in About storage on your device and in iCloud - Apple Support

including the following:

Free up space on your device

You can make storage space available on your iPhone, iPad, or iPod touch when you use iCloud Photos and turn on Optimize Storage. Or you can remove content from your apps—like photos, music, and Podcasts—or delete the apps that you're not using.