Just saying a pet is an ESA to get around housing no-pet rules will not go very far here. If your doctor or therapist feels that having an animal in yor life is beneficial to your treatment plan then they can write a letter to the Landlord or manegment company on your behalf.
Please note your pet should also have some form of obedience training just so it does not cause issues with either the landlord or the other tennants. It should be well behaved around strangers, meaning the dog does not bark or growl at them, the dog should know some basic commands like sit, down, stay, and not pull on the leash.
WHile you can't prevent a dog from barking all the time, if it barks more than a few times before calming down and becoming quiet, that may be a reason for the landlord to ask the dog be removed from the property.
The landlord may set a specific area you may use to toilet your dog, but you will still be responsible to picking up all fecal material and disposing it in the trash.
The landlord also has the right to refuse an ESA should including the ESA cause unreasonable changes be made such as a financial issue - such as higher insurance liability premiums for the Landlord (usually this would involve banned or large breeds, but would depend a lot on how the policy is written).
Again, you cannot just get your pet declared an ESA, you have to have a disability where pet therapy is part of your treatment plan.
If you have no qualifying disability then you cannot have your dog declared an Emotional Support Dog, and you should look for more pet friendly housing.