Is there a free API that returns a list of locations that correspond to the keyword?

After entering the keyword, I would like to display a list of the locations that apply to the keyword.

Please let me know if there is a REST API that returns a list of places that correspond to the keyword for free.
Also, as an API parameter, latitude and longitude are not required, and it is easy to use with an API that specifies keywords.
What I want to do is to create a function that displays the names of places such as Akita and Aomori in a list when users type A.

The environment is ios10 and the language is swift4.