I am sorry to hear about what happened to Blue. I am a veterinarian and will do my best to help.
The longer his eyeball is proptosed, the less chance that he will keep vision in that eye. He needs to see a veterinarian, have the eye put back in, and have his eyelids sewed closed to keep it in for awhile. Today would be best. Tomorrow might be OK, but there is less of a chance that he will be able to see out of the eye.
I might consider going to one of the emergency clinics as a walk in, and just staying there until they see him. If that is not possible, I would be at your regular vet office as soon as they open. Keep the eye moist with salt water (1/2 teaspoon salt in 1 pint of water) gently poured onto the eye, or applying artificial tears to the eye every few hours ( you can get artificial tears at a pharmacy).
You can try gently pushing it back in, as you saw online, but if it has been out for more than an hour or so, it may just pop back out. That is why we sew the eyelids closed for a few days after replacing the eye.
I am sorry this happened. As horrifying as it is to you, it is all too common in this and other "bug eyed" breeds. I hope you can find a vet to help you today, or first thing tomorrow. Let me know how he is doing and what other questions I can answer. Rebecca