Many pets are scared when trying something new. Its important to get your dog comfortable with the ramp before he can trust to climb it.
Most dogs are food enthusiast,so treats are going to be your best option to get your dog to try something new.
First, please place your ramp on a flat surface like your living-room floor. Then place treats around the ramp. This helps your dog become comfortable with the ramp. We want them to get used to the texture on their paws. Use treats to encourage your dog to place paws on the ramp. Allow the dog to do it at their own pace. Refrain from picking the dog up and placing it on the ramp. Be sure to give lots of praise and treats as they get used to walking back and forth on the ramp. Once the dog is comfortable with the ramp, adjust it to its upright position. Continue to give treats as motivation for your dogs.
With the dog on the couch, call the dog and they should use the easiest and most convenient route, which is down the ramp and towards you.
Once the dog is using the ramp reliably, you can move further away and continue.
Remember to give lots of praise and before long your dog will be able to climb the ramp on it own.