Yes. In most cases this is not a problem at all. We’ll need you to provide either the key number for your existing locks or a very good copy of an existing key. With that we can order the new door to be keyed the same as your existing door. This is particularly helpful if you use the same key for several doors in your house.
There are some limitations to this. For example the key locks on a common model of sliding doors will use a shorter key than a typical front door so they cannot be keyed alike. If that is critical for you we could use a different model patio door. Multiple sliding doors can also be keyed alike so three sliding doors with key locks could all use the same key. Be sure to discuss this with your window and door expert before placing your order.