I used Evan's book and DVD during the quarantine times last spring and went slowly, almost every day going back and reviewing video and book. Went great! To a point. I live in a suburban neighborhood with my versatile breed dog. I have a small backyard to work in, but some areas that I drive to everyday to exercise the dog and myself.
My dog will retrieve/hold/give dummies, and piles of dummies. Took him to the end of the book. But I need help with transitioning to hunting. So far this year my dog doesn't get it. We've done some upland hunting and he is back to old tricks.... finds and pickups the bird, but usually wants to come only part way back to me, drop the bird and go off hunting for another.
I have to travel some hours to get into areas where there are birds to hunt, so not easy to do, and I don't have supply of pigeons, etc.
During training I did use some frozen quail and he would stick to the program with those, in the yard.
Hoping Evan has some suggestions, or maybe he has other materials to take me that next step.

Pick the dead bird up and use it as if it's a training dummy. Throw it and have your dog retrieve it giving the fetch and hold commands. If that doesn't work, use whatever stimulus that you used during force fetch. I had a Lab that I force fetched using the ear pinch method and he did the same thing on his first pheasant retrieve. After I flung that pheasant around the field and he retrieved it he was good to go. The only other time I had a problem was a crippled goose that he dropped after it hit him with a wing. I went out, told him to fetch and reached down to pinch his ear when he grabbed it and brought it back to the blind.

Thanks for good suggestions, Twohigh. Makes sense.

You're welcome. When stuff like that happens, suspend the hunting or a moment and think of it as a training session. The focus shifts to the dog. Fixing the problem then and getting that light bulb in his head to go off is the primary goal cause it will mean much more enjoyment for you in the future. The guy who was my dog training mentor had a pup that dropped a crippled duck in a water retrieve after it pecked him on the nose. My buddy said, "Oh no!" and got out of the blind to address the situation. He later told me that if he had let that refusal go, it could have ruined his dog for future retrieves. The dog's gotta know that dropping the bird, refusing the command to hold, is not an option.