Let say you save resnet18

So load it firsr create a leraner of fastai

learn = cnnlearner(dls,resnet18,errormetric)

learn.load(path of model from drive)

Note i didn't write exact code

And remove. Pth extension from path above

It's simple, mount the drive first then, when you save, save as learn.save("/content//My Drive/model") and load from same path