Introduce your dog to the bottle.
First, let the dog sniff the bottle. It's new to him, so he has to be comfortable around it first. Just leave it in his presence and let him come and go.
Add some water to the bottle and shake it.
The familiar water sound coming from a new object will pique his curiosity. It might take him a few tries to figure out that the water is coming from the bottle, but he'll get it eventually.
Make drinking from the bottle the only option.
Remove all the other water bowls you have out for your dog. This way he won't have a choice but to drink from the bottle if he's thirsty. Place the bottle in his crate while he's in it.
Praise him when he drinks from the bottle.
Every time you catch your dog drinking from the bottle, give him a treat. He'll quickly associate drinking from the bottle with positive experiences.
Be patient.
Some dogs take longer than others to get the hang of drinking from a bottle. Don't give up if your dog doesn't get it right away. Just keep following these steps and eventually, he'll learn.
Remember to never leave the bottle filled with water and unattended for a long period of time. Dogs might try to chew the bottle instead of drinking from it, which can be dangerous.